apple watch ultra. nothing beats it in terms of usability especially for older people. There are garmins and even purpose build toys. The Garmins are not as user friendly and the toys are just that.
Self winding watches were a thing for quite some time.
Definitely still a thing. I'm wearing one right now. :)
I wonder if something like this could be adapted to work for this use case? The big problem I see is that a human can just take the damn thing off, and people with dementia are not incredibly reliable or predictable.