I am a massive geek and try and jump on all the new bandwagons, but try as I like, I cant seem to justify a smart home. "Turn a light off" well I am at home, I can do it myself. "Smart lock", I am usually already at the door when I need to use it. "Smart thermostat", mine saves even more energy when its off, and on when I do. I can understand smart security or video intercoms, that's cool. But even then I don't have one.
All these things need batteries or replacements or lose wi-fi/Bluetooth connection, or incompatible with other stuff, and use needless electricity waiting for the 0.5% of the time they will be used by your device. Even for me, who loves to tinker they seem like too much effort.
Two points.
(a) Yes, it's true that a lot of this stuff sucks. You mostly can't trust brands -- Wyze indoor cameras are very good value, the outdoor cameras are so so, the other devices (like plugs) are horrible. On top of that, HomeKit is currently hot garbage as far as the user interaction is concerned. (The low-level details like security and capabilities are OK, but the automation capabilities, and the app to control those, are pathetic.) And HomeKit is the best of the bunch, an Einstein compared to Google or Alexa. (And then all the pathetic wannabe's that think they'll be the only Smart System in your house, like Samsung or, god help us, the truly deluded like GE's Geneva.)
You absolutely do not want to be setting this up for someone else who is not technically inclined and has no technical patience.
(b) BUT! If you do have the patience and some dollars and are willing to experiment, it can be quite magical.
The camera/security stuff is obvious. Then there are garage doors and normal doors. But then you get lights, plugs, and blinds.
My house has lights turning on and off based on a combination of light level, time of day, motion detection and occupancy. I never turn lights on or off, they're just on at the right level when I need them to be.
The smart thermostat mostly handles temperature correctly, but in my office I also have a fan directed at my legs that comes on when the outside temperature is especially high. (Psychologically I find that when outside is extra hot, I feel slightly hotter inside; maybe driven by light and UV levels?)
The whole house fan is hooked up to a smart switch, and comes on automatically based on various rules (eg if an air quality detector detects that VOCs and particulates in the air are higher than they should be).
The smart blinds save power by covering windows as appropriate, as the sun blasts them with maximum strength, and protect my eyes from being blasted by the setting sun.
I also have a Rachio (smart irrigation system) which is super cool. You tell it about each sprinkler station (plant type, approx size, type of irrigation equipment) and your locality's rules for when you are allowed to irrigate --- important for CA and other dry states; and it controls the timing. Ramps up more water when it's hotter/dryer; less water if it's cooler, no water after it rains.
I haven't yet installed, but they are lined up in the queue, a Sense system for minute-by-minute tracking of my electricity usage (total and by device) and a similar water system (Flo or Phynn, haven't yet decided which) for water.
In a sense these are all small items. But in another sense that's what a smart house is. It's not going to change your life -- it's not a wife replacement, or a car, or a new job. But it makes every day just a little smoother. I smile every day when I hear the blinds going up or down as they track the sun, and know that my little house is working hard to make our lives just that little bit nicer, to remove the irritation of a room that's slightly too hot, or setting sunlight overwhelming yor vision.
My personal philosophy is I'm willing to spend about $100 a month on this sort of experimentation. For some people maybe you want to halve that. But $100 a month gets you a surprising amount of equipment. And my experience has been that the delight I get from the $80 or so that is well spent amply compensates for the $20 or so that turns out to be a failure (product category is just a bad idea, or the category is great, but the particular model I bought sucks.) Right now you do have to keep experimenting -- that's the breaks. Are the Ikea Smart Blinds better than MySmartBlinds? Well, truth is you won't know until you try at least one. You can read the reviews, you can try to think it through; but you just won't know what works for you and what doesn't until you try. (For most things -- cars, fridges, TVs, ... -- we have enough experience throughout life, from using different models in different homes, that we mostly know what we want from a car, a TV, a stove. But for smart devices, you just don't know until you try and experiment!)
Do you want a colored smart lightbulb? Who knows? My experience has been that color is mostly not worth it (except that when I go to sleep the light in the closet goes to a very dim red as a nightlight). But to learn that I had to get a basic bulb (just on/off+brightness), a color temperature bulb, and a full color bulb, try all three in different locations, and track over time what functionality was actually useful vs what was not being used.