I mostly disagree with you if you work in a "standard" company - it's usually "make a form" or "move data / do some other CRUD". These tasks don't generally have that many unknowns.

It's absolutely valuable for managers to be able to estimate velocity as well, though the problem is that they really do stop understanding "we are not sure" once you spoil them.

I am a consultant too, so it's critical for me to say "we are delivering this, in this much time", even though we are "agile".