I rehabbed a rental house that I made into a smart home. Samsung Smarthings hub, GE switches, amazon alexa.
I planned it to be not associated with my personal accounts and actually set up a Gmail account with the address of the house. All things run through that email address.
If we ever sell the property, I’ll give them the credentials. But as far as tearing out light switches, etc. Nope.
It would be like someone selling you a 1970s split level with that gosh awful intercom system and the buyer saying “can you take that with you?”