Or the weather. Or the real time price of electricity. Or high-demand periods. Or the learned heat retention capability of a particular home. Or a ton of other things that have never been implemented.
I actually dropped my Nest thermostat for an Ecobee. With the temp sensors it’s been vastly superior.
My house has two floors but a single Hvac zone. The ecobee is set to consider temp from both upstairs and downstairs during the day but only cares about upstairs at night. It also circulates the air in the house every hour for a bit.
The end result has been far and away better than before in terms of efficiency and comfort.
I'm an Ecobee user as well, what I really want is better vent control room-by-room and I want it integrated into the thermostat.
There are companies like Keen selling net-connected vent baffles, but the price is still really prohibitive. Like $1500 to do a house prohibitive. And then it's still not integrated with the thermostat.
An Ecobee-compatible vent baffle for $30-$50? That would be a no-brainer.
Because the market is actually pretty small for expensive thermostats. I bought the original version of the Nest thermostat because I wanted to remotely control it via my phone. Most of the smart features are horrible, the AI is dumb, and the fact that controlling it depends on a server that may be EOL'd scares me.
Most thermostats are in the neighborhood of $25-$50, so $250 for a thermostat that offers marginal utility is a hard sell.
I think at some future the point the utilities are going to be more involved than they are right now.
At this point in time you see some utilities offering setback thermostats (smart and non-smart) as a way to help smooth demand during peak usage periods.
Some of the better ones run promotions and offer rebates on Nests and Ecobees, but these units still are completely dumb when it comes to talking to the utilities. My electricity provider has real-time pricing and smart meters (with Zigbee interfaces) that are connected to HQ, but there is still no way to move that information to the wall unit. They offer a 3G-connected modulation unit for A/C compressors, but that's directly connected to HQ and the consumer has no other way to interact with it other than overriding it.
If things really start getting bad out there (e.g. Texas this week^), that will be the motivation to improve this ecosystem.
Everybody who gets a smart thermostat needs to keep their old one in a box for the day the server gets EOL or the device and/or network gets hacked. When that happens, you aren't going to be able to go to HomeDepot and buy a new dumb thermostat.
Dumb thermostats will always exist. You could also preemptively wire one up right now in series with your smart thermostat to act as a safeguard against extreme settings.
Because no one actually gives a shit about $0.50 savings per day.
Nest isn't popular because of its functionality, it's popular because it's associated with Google and trendy to own. It's going to be hard for another company to break into that market.
