Mastodon and Firefish have been good alternatives for me, not to mention, they're part of the same fediverse as KBin

Libreddit does work, but not all instances of it do.

beehaw - tight-knit diverse, lgbtq and positivity reddit

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

Out of the open platforms, I use:
Reddit: Lemmy, Beehaw, Kbin
Twitter: Mastodon, Calckey
Facebook: idk nothing really plus I don't even use Facebook that much anymore

I may occasionally use proprietary ones like Twitter, Tumblr and Threads.

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.

On the other hand, it makes spammy articles from content farms the primary resource to find answers.
And either way, not everybody is doing this, so Reddit retains part of its usability, which still exists, and some portion of people will still use Reddit after the API changes.