Time/working hours and pay.

It'd be nice to have a company with only CTO-level engineers, but no one can afford that or even find enough workers at a certain scale, regardless of pay.

It makes sense that with AI, you can have architects who haven't written code in 5 years produce acceptable code, but I don't know many people high up the chain who'd say they have the time or desire for that.

Until your level's backlog is empty, you'll always find something better to do than the tasks of your lower-level colleagues, and it'll never become empty.