Mastodon getting some attention is actually pretty good. It’s one of the first times in a while where an online social media network is largely free from corporate control. The code is free and open, and there’s no algorithm pushing ads and PR - just a chronological feed of people you follow. And it’s definitely more hospitable to leftists than Twitter is, since leftists will always be able to host servers and moderate them.
Hopefully more leftist servers come about, but in the meantime, you can find any server that has a decent description and rules and join that. I recommend sorting by uptime and open registration.
Things have improved but like many things in our culture, it is still difficult for POC and other marginalized folks to feel at home.
This was one of the first things I’ve noticed when browsing Mastodon. It is completely full of mayos. I don’t think I saw a single face avatar that wasn’t a white person, usually a white man. Say what you will about Twitter, but at least it isn’t mayo city. The percentage of Black Twitter users is slightly higher than the percentage of Black people in the US.