There’s absolutely no need to build them yourself, there is a need to simply not buy always-online vendor-lockin devices. It’s not something for people who don’

There’s absolutely no need to build them yourself, there is a need to simply not buy always-online vendor-lockin devices. It’s not something for people who don’t know about computers or can’t run their own mini-server like an rPi, but it’s still far easier than building something yourself: https://home-assistant.io https://home-assistant.io That opens up an insane amount of smart-home devices that require no internet connection at all.