Uh, instance mods don't have more power than admins on other platforms. dang can Thanos snap you from existence on this platform at any moment: how is that for having a say on what you can do?
What you complain about is that you hear a lot more about the moderation on the fediverse than you do on HN or Youtube, despite Youtube moderation practices impacting a lot more people than the sum total of what happens on the fediverse.