When the company is smaller you get managers that are genuinely interested in growing the company – because that's what they grow too. Forget the 'mission' and such nonsense, noone truly cares about that. And the people that are highly visible early on tend to keep on growing their influence, organically.
However, at a certain size, they don't grow all that much if at all. Sure, the company might still be growing on sales numbers, but it's still mostly static. Some new divisions may pop up but they are usually satellite operations that may or may not matter in the long run. The next best alternative is to fight to move up the reporting chain. That means company growth or wellbeing no longer matters; in fact, cannibalizing existing products or whole divisions or bringing them under you is how managers grow. They do not care who or what they have to step on to make that happen.
I would do all I could for a job that respected me as a human being. But it’s gotten to the point where you can’t trust anyone above you, no matter what they say. Doing well in a growing company means you have to get more and more cutthroat, so you’re incentivized to try less and less.