Nest 1st gen and 2nd gen thermostats no longer supported from Oct 25

Kind of an apples and oranges comparison though. Analog and simple digital thermostats are very simple while something like the nest is running 32-bit OS. Complexity increases cost.

>Complexity increases cost

Not really. The BOM of a smart thermostat is nearly equal to a dumb one right now. What adds cost is reliability. Hardware reliability costs engineering time and expensive component choices. Software reliability requires engineering resources and a mindset beyond optimizing quarterly returns.

There is no legitimate reason a fancy thermostat should be e-waste after ten years.

Why does it need to be complex? It is just managing temperature same as the analog one. Same wires to the furnace and ac. Setting a schedule shouldn't require a heavy OS on top of this. One way I came up with in 5 seconds, just have it sit on the network and take in emails with your schedule changes and you're done. Or just ping it, don't even need the mail setup. Should be pretty light and performant with not very many lines of code.

To be fair the cheapest thermostat sold at homedepot is probably super reliable since it is using a very simple hardware stack. It isn't like this stuff really ought to go wrong very often. Maybe you break a solder I guess over a lot of heat/cool cycles? It's just a thermometer and a switch.