So from my experience: Good manager is like UFO - I've heard of it, but never seen one. Unless you consider top management that just makes itself invisible and leaves kids on the playground doing whatever they are inspired to. That would be probably closest to what I could take as good management.
Invariably though, these guys were in the trenches at one point. Good developers or designers that eventually rose up into management. They understand how it's better if everyone works together instead of get too deep in politics (they aren't perfect about that, though, I've seen them have favorites) and try to enable their team as much as possible.
The types of things you're talking about like manipulation et al., I've only seen from career managers, who never really had a proper job making things. And those definitely exist, and are more plentiful than the good managers, but the good ones aren't mythical creatures. You're just getting unlucky in finding them, I guess.
I soothe my ego on the anonymous internet. In the workplace, it goes in the fucking box and every other thing I say is a variation on "I don't understand". Working life is so much easier without ego games. So much more pleasant.
I hypothesise that programmers with excessive ego have been sadly let down by managers and team leads in their formative years :(
But managers are still the norm. If it were economically preferable to not have managers, I think you'd see that model gaining lots of traction.
Maybe this is a common model though, I'm not familiar with very many truly flat organizations.
Sure, sometimes a group has relatively simple tasks and doesn't have enough incompetents, prima donnas, social disaster zones or or straight up sociopaths to need a good manager, but given that a good manager can massively improve the output of a team, make everyone happier and make a company more profitable, it seems silly not to have a good manager.
In the interests of no passive-aggressive nonsense, I simply don't believe that you've never encountered a situation where a good manager can make things better, or never encountered a situation where somebody was managing things and in doing so making a positive difference. The odds against it seem astronomical; especially in a 750 personnel sized company.