Yes, that's an important thing to remember. Instances like .world and justshit are largely responsible for dragging down .ml and other (relatively speaking) decent instances. On hexbear, we're used mostly seeing ourselves (obviously), lemmygrad, .ml, a little bit of db0, and a smattering of other little instances. The second you go on .ml, you're inundated with loads of the same shit we all thought had been left concentrated on reddit. It's not that .ml is that terrible, it's that it's too small to push back against the hordes of .worlders. And so the culture of .ml and other smaller instances slowly but surely gets degraded. Defederating from hexbear and lemmygrad preemptively by .world wasn't done just because they wanted to be "safe" from having to see opinions and takes based in a reality they like to deny (it was that too), but also so they could hold sway and more easily influence and dominate the fediverse.
For everyone on hexbear that was gung-ho about federation because it would mean actively dunking on libs, if you were one of the ones (like me) who liked the idea of arguing with liberals and putting them in their place for all the lurkers to see how inept their worldview is, I very much encourage you to make accounts on other instances and help push back against .world's insidious shit. If you're a hexbear that has had enough of that shit and just want to chill in a leftist space, I completely respect that and would suggest that you not make accounts on other instances.
Hexbear has almost fallen back to a state of existence similar to how it was before federation happened, with the biggest difference being more cross pollination with lemmygrad. Which is good for those I just mentioned who like to not have to see liberal and chuddy garbage outside of the dunk tank. But it's not good for .ml that they get so swamped by .world. I've said it before but I really do encourage hexbears who like the posting trenches to make accounts on .ml and check the same threads you read as a hexbear and take note of how drastically different the experience is.
I'm gung ho on federation because hexbear sucked ass pre-federation. Just a bunch of people congratulating each other on not being on Reddit, in between struggle sessions about dirt paths or tofu or whatever. When that wasn't happening we would be focusing on one part of the site that we deemed wasn't good for culture or whatever (looking at you, news mega haters). It was flush with power users that got treated with kiddie gloves because "that's just how they were" and any pushback got met with immediate hostility.
Federation brings in new blood, keeps people on their toes, has made mods less tolerant, and made people realise that their mortal enemies isn't another hexbear user who has a somewhat different reading of Lenin or fried broccoli wrong or had a mass grave of outdoor cats (joke)
I seriously do not understand the people who pine for pre-federation days. The site was stale and an ourobouros of personal grievances shielded in vague-posts in between reposted 5 year old memes from Reddit which we were glad we were better than.