That “smart thermostat” thing is a remote operated cutoff for your AC / heat and water heater ... could also control heavy motors like a pool pump , they state xx minutes off in a xx hour period but they always seem to exceed the promise when they’re short on power, the purpuse is to let the electric utility run their main generator (coal , nat gas , oil ) up to VERY near full capacity and then spike demand when it gets critical long enough to fire up their secondary generators (basically jet engine driven), it keeps them from having to fire up the jet engines as often saving them fuel.. typically they offer peanuts ... not worth it ... I tried it maybe 20 years ago and had the box go bad ,, lost AC and hot water for a few days .. not cool...
This device you mentioned is not what people are being fee’d for refusing.
Have heard others with same complaints about the smart thermostat. That thing I would fight against.
Smart meter, living in the country I’m happy to not have some stranger just showing up on my place. Who knew if they were for certain from the power company?