I've been buying smart home devices for many years. I love some of them and would absolutely buy them again if they stop working. However, I have different types of smart home devices that I would not replace equally because better options are available.
Smart light bulb
An intelligent light bulb was one of the first Smart Home technologies that I have ever bought. It was impressive to be able to control my lights on my phone via an app and to change the color or color temperature of the light bulb. However, intelligent light bulbs have a big mistake that makes them useless most of the time.

Meaning / Philips Hue
Smart light bulbs require a power and this power is only delivered if your light switch is switched on. If you switch off your intelligent light bulb with the switch on the wall, it no longer has any performance, which means that you cannot control it remotely. It becomes a stupid light bulb again. If you live in a house with other people, it is not realistic to ask you not to use the light switches in your house.
In the future, I will instead install intelligent switches in my house. You can control an intelligent switch to switch on and off your lights, but since it is always connected to electricity, you never have to worry about it cannot be reached.

41i+Z-JR+ZL._SL500_
Kasa Smart Light Switch HS200
With the HS200 you can control everything that controls a standard light switch control – all from your phone. Switch off your lights, ceiling fans and other devices on and on, no matter where you are.
A smart home control panel
The idea of Smart Home Control Panels seems to be a good thing. Having a central hub from which you can control all Smart Home devices in your home seems to be useful. Everyone in your house can use it and you can even get visual feedback on the condition of your house.

Amazon
In my experience, however, a Smart Home -Control Panel is simply not much used. If you want to control your Smart Home devices, you have to go where the Smart Home Control Panel is located. No matter where you place it, there will be many opportunities in which it is not nearly where you are.
My goal with my smart home is more automation than for control. I want things to happen without my input, how to turn on my lights when I go into a room. A Smart Home operation is effectively only an expensive set of switches that are recorded on your wall, which is not that smart at all.
I have an Amazon Echo hub and honestly I can't remember when I last used it to control a smart home device in my house. In most of the time it is used to show my current gas and electricity consumption and my prices that are drawn by the home assistant. In other words, it is just a glorified display that I can easily replace with an old tablet.
Echo devices
When the first Amazon Echo devices appeared in the scene for the first time, it felt like it was a real game changer. If you use your voice to ask for information, play your music or to control your intelligent home devices, it felt like we were living in the future.
However, very little has changed since the first start of the Alexa devices. I am constantly doing “Keeping with Alexa” -E -E -Mails from Amazon with information about what Alexa can do, and there is never anything new. I was quite excited about the announcement that an improved AI-driven version of Alexa came, but we are still not closer to the fact that it happened.

Amazon
The other main problem is that everything you say about Alexa (and possibly things you don't) are sent to Amazon server, which is not ideal for privacy. Fortunately, things begin to change. I run a home assistant -server and recently a Smart speaker from Home Assistant was published, with which you can create your own voice assistant who is able to carry out locally if you have a suitable hardware in your home.
Home Assistant Voice is currently only a preview edition, but after all, I hope to replace all my echo devices with local voice control that is more privately and much more adaptable.
Kluge blinds
The idea of intelligent blinds is great. To be awakened by natural sunlight while your blinds open, automatically sounds of the perfect way to start the day. However, I found that experience is less than perfect.
I chose Ikea Smart Blinds because of the low costs, and the first problem is that they just don't look so good. You have in every color you want, as long as it is gray, which is at best not inspired. They work well and do their job, but they are not the color we would have chosen when choosing.

Ikea
Another big problem is that the rechargeable batteries are at the top of the blinds. To charge the batteries, I have to climb up some furniture to reach them, which is annoying quickly.
I wish I had gone instead for intelligent blind buttons or intelligent blind drivers. You can use them to control your existing blinds so that you can dispose of any desired color of any blades. They are also much easier to fit because you only have to install the controller a completely new blind.
There are also similar options for curtains, so that you even have curtains over your blinds and both can control both if you open your curtains and raise your blinds if you want to let the light in.
Ring doorbell
Until recently, I had two ring video for our home, which have two front doors with a peculiarity of design. I was satisfied with the products when I installed them for the first time, but as with so many technical products, they seem to have gotten worse over time.

ring
The detection of the person is horrific, with so many false positive aspects that I had to switch off the motion warnings because the doorbell would tell me that someone was at the door when the wind changed the direction. In order to make things worse, ring increased the cost of the subscription that I had to save and access video recordings.
I finally gave up and replaced it with a Rolink video door. I not only have a local memory by connecting an SD card to the device, but I also linked it to Homekit Secure video so that I can access my recordings from a distance without additional subscription.
Everything that requires a proprietary hub
At one point in the life of my smart home I had almost more smart home hub than I had Ethernet connections, and that belonged to the replacement connections in the knots of my Wi-Fi network. It is incredibly frustrating that so many Smart Home devices need a proprietary hub to work over the box.

Ikea
I had a hub for my color lights, a hub for my Ikea jalousia, a hub for my Zigbee sensors, a stroke for my intelligent thermostat and much more. It started to get out of control.
Fortunately, with the help of a Zigbee dongle, I replaced the vast majority of my smart home hubs by connecting directly to Home Assistant. For example, I could connect my IKEA Smart Blinds and my Philips Hue Smart light bulbs directly to the Home Assistant to Zigbee without proprietary hubs. I now have a hub to rule them all, and it was a real pleasure to take the chaos of the cables off behind from my router.
Smart home devices that communicate via Wi-Fi
There are a large number of smart home devices that communicate via Wi-Fi. It makes sense because it means that you do not need any additional hubs as your router to control your devices and ensure that you can access Cloud services.
However, there are many disadvantages from Wi-Fi Smart Home devices. Wi-Fi devices must communicate directly with their router. So if you want to install a smart home product from your router far from your router, you may find that it causes serious problems due to the weak connection. If the Wi-Fi sinks, your smart home devices may quickly become stupid.

TP-link
Your Wi-Fi network can also be quickly overloaded if you absorb several Wi-Fi Smart Home devices to the mix. In the case of several people in the house, all of whom use WLAN at the same time, your smart home devices can become unreliable or even completely lose the connection.
In addition, Wi-Fi is relatively powerful, so that all of your Wi-Fi Smart Home devices need access to sufficient performance. This usually means that they have to be connected and restrict where they can place them.
However, Wi-Fi is not the only option. Devices that use alternative communication methods such as cigbee or thread can form a network network in which each device can pass on information to the next. This means that even the most distant device in your house can maintain a solid connection.
The low electricity needs of these protocols also mean that their cigBE or thread devices can be executed solely with battery flow, so that you can put them wherever you want, including places where there are no streams such as bathrooms.
With so many Smart Home products, it is not always easy to know what devices are suitable for your needs and which will be less useful. Sometimes you just have to suck and see it. As soon as I have invested in a product, I will try to make the best of it, but at some point products have to be replaced. At least now I have a better idea of what I want and what I don't do.