The one "smart home" thing I've done is a garage door switch hooked into Apple HomeKit. I have Home Assistant running on a small server, just for kicks, but mostly it serves as a quick dashboard for my network devices.

But being able to control my garage door when I'm not home is definitely very useful. Get a RATGDO and it's entirely local, no cloud. Use your remote access solution of choice to get into your local network to operate it.