out of all the people who went for more power(written on the side of the box as max
possible value) and thought it was an improvement, how many made proper measurements to check that the main change in audio was indeed power related before they decided to run their mouth?
all you know is that you tried 2 amps and you preferred one of them. 2 totally different amps, with different designs, different specs, different components. so how did you go in your head from the fact that almost everything is different to, thinking "it's power I know it"?
instead of trying to see what might align with your preconceptions, try to disprove your reasoning and see how that works.
as for why you think your rational is fine, sadly we're wired that way:
https://en.wikipedia.org/wiki/Apophenia
https://en.wikipedia.org/wiki/Confirmation_bias