Esports training is about beating the competition, so you have to chase every last improvement possible, and there are diminishing returns. For ordinary GUI use you can compromise on 99% performance with much less effort. This is still more effort than most computer users put in, but it's hardly anything compared to what professional musicians or athletes have to do. There's nothing absurd about it.

As an example of a compromise you could make, in many games, mouse acceleration has higher skill ceiling than linear mouse control. But mouse acceleration it's harder to learn, and the possible performance improvement is only small. I disable mouse acceleration myself because I'm not aiming to win tournaments. IMO, linear mouse control should be the default.

And I do not experience any conscious effort when using a mouse. My subjective experience is I look at a target and the cursor appears there automatically. The better the hardware you're using the easier it is to achieve this.