People like me writing code who are, supposedly, specialized in writing various kinds of writing software/building things and various aspects thereof, by and large.
P.S: Its the same with every/any profession that exists on earth.
Well, if you want to program/do tech for multiple companies, that's pretty easy: it's called contracting or consulting. It pays pretty well, too, if you're good at it.
Somehow only grass root level employees are asked to make these concessions.