There are several closed group options or other closed source ones that aim to be just like Reddit in practice but not exactly it in theory. Ironically the Reddit alternatives sub on Reddit is probably the best place to get such a list 😜.
I enjoyed Squabbles for a bit - it was described at the time as toxically non-toxic as in very much anti-hate speech, though I don’t know how it’s fared recently. At the end of the day though it’s just one guy’s project, and while he’s no Huffman, still the entire thing turns around him, very unlike the Fediverse that can become anything we want it to be.
If you do remain on Lemmy, learn which things to block bc that will improve your experience substantially. Just blocking lemmygrad.ml and hexbear.net improved mine 95%, and ironically some people (not me) also block Lemmy.ml. You will come to find what works for you, I am just saying that the experience varies enormously depending on that one factor!