I’d say the problem with bias isn’t that it exists, but when it’s covert. The ML instances were covert for a while if you weren’t paying attention, LW is “centrist” and “neutral” which means it defaults to a vaguely conservative position (conservative in the sense of being passively okay with the status quo, not the US sense in which conservative is an electoral party), but it remains covert simply by being default.
It also has open sign up which means anyone can sign up, which will tend to attract people who know their politics suck, so it will tend to attract unpleasant users.
Another instance with open sign up is sh.itjust.works which I’ve noticed a lot of the more toxic assholes I’ve dealt with come from. I imagine having profanity implied in their name doesn’t help with that.
Whereas instances like lemmy.blahaj.zone and beehaw.org wear their bias on their sleeves and require sign ups be approved. I chose slrpnk.net for a similar reason. These instances seem like a much nicer experience in general, and I would recommend anyone wanting to join lemmy find an instance that they like that has an approval process.
I think the fediverse presents a vision of an internet based on trust, and I think that sign up process is an important place to start building that trust.