Given how much potential there is to make a vastly superior Nest-like thermostat, why hasn't anyone done it?
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.
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.
Most thermostats are in the neighborhood of $25-$50, so $250 for a thermostat that offers marginal utility is a hard sell.
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.
^ https://www.bloomberg.com/news/articles/2019-08-12/searing-t...
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.