Webers law is about perception of detecting a change, not the outcome or what happens to you mentally or physically if you do or do not notice a specific change. Our bodies and minds are not precision calibrated measuring instruments.

It also does not trump physics. I may or may not NOTICE an incline change from 0.0 to 0.1 but no matter, it will take more power and energy to maintain the same speed. On the flip side people actually do claim to notice the smallest things like the 30 gram weight difference between two different cassettes when the combined weight of them and the bike could be 180+ pounds and that 30 gram difference is a 0.037% change and claim it had an impact on their performance but yet they themselves could weigh 500 grams different one day over the next but they don't notice that?

I'm not arguing anything, I just don't believe some of what people claim to notice and if them noticing or not had any real impact. Same like the butt dyno related to a car performance. It is terribly inaccurate.