Because for salaried knowledge work, the premise is that your impact or output and not the hours worked is the basis for your compensation.

Suppose someone (pre AI) wrote 100k lines in 50 hrs/week of bad code but someone else wrote 10k good lines working 40 hours. In theory the former person would not be the high performer.

I agree many places don’t work that way, but also many do - so it’s maybe a hard discussion to have broadly and not scoped to the individuals limited experience.