The energy used for such activities is another question.
If I see 90%+ CPU load (being "efficient"), I need a bigger CPU.
If I hardly see any CPU load, I am being effective.
Ergo, the biggest CPU I can afford is the best choice.
I don't consider unused CPU power as waste, I see it as relief from worrying about capping out.
Edit: I accept your findings, and will pay closer attention to see if I can see the same.
These have been 7th gen and higher i5/i7 machines and newer J4xxx series celerons.
Haven’t had any AMD kit to compare though.
Let me put it a different way: If I'm playing a game and I'm barely using 20~40% CPU, I'm doing good. That 60~80% unused CPU processing headroom is my ability to be worryfree about capping out.
Which is to say: Yes, my 12700K is massive bloody overkill for my day to day activities, but it is 300% adequate for my needs and concerns and I love it. I'll probably upgrade it to a 13700K or 13900K(S) depending on the price a year or two down, since my mobo can accept it (thanks Intel!).