This does sound interesting, but it's harder to do this with a junior heavy team. While there are certainly juniors who can get things done with minimal direction, there are also those that do need to be taught how to communicate and collaborate effectively, and especially how to work on things that matter.

In that case, it's hard to move to a manager of one, as some people have to support more than a single mentee. And they end up being consumed by their "managerial" work, i.e. being a manager instead of an IC.

But, this does open the question: can you build a team structure from the ground up, even a large one, where you've got managers of one only, but have a reasonable seniority structure (eg. a software engineer with 2 yoe could manage someone with 6 months or less).

The very best managers I've had, I only interacted with 2-3 times a week. They would tell me what the company's priorities were, and assign projects, then step back and say, "there you go, do it however you want, work with whoever you need, let me know if you need me to move any roadblocks out of your way."

I've had good and bad managers, and the best ones were always ones that were good at doing something. Even if it was something less related to what I did on the day to day it's nicest when someone levels me up vs mostly being the communication glue between me and the rest of the company.

Eh, doesn't this just increase the office politics when it's a free for all?

IME, "office politics" are only an issue in companies that have a competitive (toxic) culture. I've (very thankfully) only worked in one of those so far and I lasted there less than a year.