You are criticizing the verification system by comparing it to ProtonDB which, again, is a different thing.
Different in some ways but serves the same purpose.
Steam’s verification isn’t “inaccurate,”
Yes it is.
Crowdsourcing something like that would not be a good way for Valve to accomplish its goals.
Yes it would.
0.1kWh per hour? Day? Month?
What’s in your system?