I don't care about getting promoted in my current role (at a small start-up where the eng org is flat), but I'm miserable because there's obviously a clique of people who are "trusted" and take over the technical direction of anything interesting. What's left is basically just implementing their ideas and then having them rewrite it on you or nitpick it in PRs until they practically wrote it.
I’ve worked in places with nasty politics. It’s brutal and awful.
In a smaller place with a flatter org, you’re usually going to have less nastiness, for the simple reason that there aren’t any bullshit roles with organizational power. Bullshit attracts assholes.
When small companies suck, it’s usually because the owner is a jerk.