I’ll buy cynicism around the data collection aspects of these things but one only need to look to the desktop application marketplace to see the broader trend.
I’ve supported both self hosted & cloud hosted products for money. I know which one I prefer to work on and I’m surprised anyone in tech would disagree.
If my nest isn't connected to the internet, I can still go over to it and turn it and the heat will come on (or go off). If my smoke detectors can't talk to the internet, they'll still work like a regular smoke detector. And even control my Nest through it's own mesh network (If I want them to). I can't speak from experience, but I'd bet that my garage door remote will still operate the door even without a wifi network to sell my open/close times to the highest bidder.
Regardless, I don't think Craftsman is interested in my garage door habits; they're interested in selling me a new garage door that I otherwise wouldn't think I'd need to upgrade. Smart home functionality is just one way to get that sale in. And it apparently works.
It's not understandable nor acceptable if my appliance within my home with no inherent external dependencies doesn't work unless that link to somewhere else is working.
> This is obviously false or else devices like this would have been trivial to make and seen some success...
Rubbish. There's simply more economic incentive for companies to create devices which siphon off usage data for them to sell.