Mastodon: open-source, in the fediverse, open for signups (depending on the instance)
Bluesky: proprietary, invite-only (for now), not in the fediverse but has its own network of domains

And I have nowhere to go but Kbin because Beehaw is unstable and I don't want to open up a fourth account. Accumulating fediverse accounts should be the last thing you do

"Third reply downvotes" and other types of bullying done for absolutely no reason. Also, people misleading others to disgusting communities just to troll them, for example (and I am paraphrasing the names of the communities): "misspell the community's name to c/vercute instead of c/verycute and you accidentally get a sub full of gore" or "check out c/audioing, it's definitely not people doing a very disgusting thing to one of their body parts". I do, however, like the fact they're bringing the whole subreddit swap meme - for example: on Reddit we have had r/trees and r/marijuana_enthusiasts and I've seen that implemented into Lemmy instances already. I wouldn't get rid of that, I think there are some traditions that are neat and don't harm anybody.

I think that the moment YT starts actually blocking people who use ad blockers, we need ot start pushing for the adoption of PeerTube the way we did for Lemmy, kbin and Mastodon.

It feels different to use fediverse-based forum sites, but they're growing rapidly, and you find new communities/magazines pretty much every day, and even though there's some fracturing going on (need I remind you of Beehaw defederating from .world).
I like this a lot more than the social media-esque approach of modern Reddit. It has very much become like Twitter, with it's endless feed of dopamine-inducing algorithms and whatnot. The blackout is a bit annoying, but I agree with the fact people should protest decisions if they ruin things for people.
I'm liking the experience so far.

Native apps? Because I sure hope so.

They did make a poll and then later announced they'll be banning underage anime art and IRL imagery . But not art of cute/short characters because it's impossible to discern if they're over 18 or not. It's the whole Pokemon debate all over again.

So, it is recommended to either join one that fits your niche or maybe to self-host?

According to fedidb.org, the entirety of the Lemmy network (that uses the Lemmy software) has 140,442, while the entirety of the KBin network (that uses the KBin software) has 32,830.

Like this one I'm on right now.
(Tbh, I'm surprised how much kbin and lemmy are compatible with one another despite using different codebases)

I like the site, it helps me a lot.

I was never able to sign up or log into Beehaw. It's very limited in terms of who it allows to sign up, and the waitlist is probably incredibly long.
This cutoff means that I'll have to live without being able to participate in a lot of discussions, which defeats the purpose of joining the fediverse entirely.
It's just as useful to me as using Reddit right now, even less so with how much less popular Lemmy instances are currently.