Ask HN: What do middle-level managers do?

I'm an individual contributor at one of the big software companies (FANG). I'm curious about what middle level managers do in these companies. Specifically, my manager's manager, the ones between the CEO and first level management. They seem busy all the time (they are usually not at their desks). But they are never in any meetings. They never send any emails. And they don't seem to affect the direction of projects in any way. And I'm just too scared to talk to them. So asking here: what do they do everyday?