Smart Home has kind of been my hobby for the last 7-8 years. I have well over 100 devices controlled by my smart home setup.
Before I installed the first smart device in my home, however, I had a single requirement: EVERYTHING MUST FAIL NORMAL. By this I mean that if the internet went out or a vendor went out of business or I rage quit a vendor, then the device in question had to act like it was a normal non-smart device.
I avoided things where you had to configure power-on default behaviors, and where you had to cycle power or disconnect the device to reset it. For this reasons I have no smart light bulbs in my house. I replaced every light switch with a smart light switch, and if anything goes wrong, walking over and using the switch will turn the light on or off.
Most of my automation is "zero touch" flavored - I want the house to do what I want without me triggering anything. For instance, I have luminance sensors in several rooms and during the day if it gets gloomy or overcast, or near dusk, it turns lights on. I also use occupancy sensors to turn lights on and off, and have multiple rules to set lights to the appropriate brightness based on time of day (after bedtime, the lights still come on when someone goes in the bathroom, but very dim, etc.). All this happens locally via HomeKit or HomeAssistant. And, if automation fails, then the switches still work.