So it's similar to "Andy and Bill's Law" [1]: "What Intel giveth, Microsoft taketh away".

If Windows would stay the same (and not grow) it would be much faster on newer CPUs...

[1] https://en.wikipedia.org/wiki/Andy_and_Bill%27s_law

Yes, it addresses your second point.

I'm not saying your entire point is invalid, just that half of it is not correct, and so things might turn out worse than expected.