The thermostat is an ecobee, which is a pretty polished IoT device but I'm frustrated i couldn't get something _more_ local. It speaks homekit so I can do a number of actions entirely locally, and if the internet is down it still works, but I do wish it were more self-contained. So again, if I sell or get angry at technology and chuck my HomeAssistant Pi out the window, the thermostat will just work as a thermostat.
Likewise, my blinds are motorized--but they have a working remote paired directly to them. It's incredibly convenient to raise the blinds in the morning for some sunshine automatically and close them after sunset, but they'd work perfectly well without a smart home.
If you purchased my house, you probably wouldn't even know to rip out the "smart home" components because they fail over to just being normal components.
It is not particularly hard to make this method of operation happen, although it admittedly requires a budget above "dirt cheap."