Tbh this isn't even unique to Lemmy. Even on reddit, creating a new subreddit is free. If you don't like the moderation or the general vibe of a subreddit, create a new one and build the community that you like. with the ethos that you see fit. That's how there's r/gaming, r/truegaming, r/games, r/pcgaming, r/gamernews, etc.

Reddit also only allowed comments in 2008, and Digg v4 was released in 2010. Therefore much of the reddit "canon" was developed after the Digg migration (e.g. today you tomorrow me, cumbox, forthewolfx, swamps of Dagobah, discoball, jolly ranchers, double dick dude, taco show, broken arms). Digg didn't have custom communities. Reddit did. And now Lemmy has custom communities in infinite instances. If there's going to be a Quit Reddit Day (maybe July 1st?) like Quit Digg Day, we're in the forefront of shaping Lemmy.