Since most people are talking about the sign-up barriers, I’ll mention culture and reputation.
I love Lemmy and Mastodon, but whenever I’ve seen the fediverse brought up elsewhere, someone inevitably shuts down any curiosity by suggesting that it’s a political echo-chamber. I don’t think that’s accurate for all of it, but if that reputation is out there, we probably need to make an effort to show that there’s a broader appeal. If the average person is expecting the fediverse to be the left-wing equivalent of something like “Truth Social”, I could understand the reluctance to adopt it.
Exactly this. When online platforms become too homogeneous, any deviation from the typical opinions that are shared seems like a terrible, inexcusable offense that someone must do something about - thus, reinforcing the bubble.
We need to be able to disagree with each other and still get along.