you hit the nail on the head. The main issue here is also that MOST employers/managers don't really know how to measure your productivity, especially in modern software engineering.

That's why "Busyness" and "Butts in Seat Per Hour" are seen as proxy for productivity. That's also why politics play such a big role.

Until we find a GOOD way to measure productivity, Control and "Busyness" (the illusion of productivity) is unfortunately not going to go away.