Because someone's paying you to do stuff, and they might like to know what's happening. The incredible rush of money into tech in the 2010s might have given the impression that that isn't a thing, but it is, and teams that can't self-manage (including giving visibility and predictability) are going to become encumbered with more and more people managers to compensate.

What they should be doing is understanding their role, making sure it's fulfilled, and then taking that cash that would be spent on managers and spending it on engineers instead. But that won't happen if they can't communicate, or can't even see a need for communication.