I suspect it may be a bit more banal. My suspicion is that it is positioning itself (p much identically to fediverse, like will said) in opposition to the free-for-all of twitter. With the assumption that maybe people should be kept apart along ideological grounds or the meme political compass grounds, that this would be healthy and friendly (and yes create 'safe spaces').

I don't think they anticipated just how much in-fighting there is, especially on the left. Probably the most famous example are TERFs who are traditionally on the left, or another famous example some of the left cancelling zizek for his stance on immigration. But it's this with every decreasing bubbles, with no difference tolerated. I imean it's not even about tolerance, these mute lists will automate the whole process, and even by associations lol. How small can these bubbles get and is it worth having?

Maybe they're right tho, maybe this is the only way to do it. I would like to think not. It might be the only way to do it for this v particular personality - Left Twitter 2015 nostalgia user. ¯⁠\⁠_⁠(⁠ツ⁠)⁠_⁠/⁠¯