With Lemmy - I can block whomever is bothering me and I will not see their posts ever again. I can see their notifications and they somehow can keep responding to me (which ought to be worked on). But erasing their existence on my end should be a thing when you don’t want to deal with them.
Lemmy and other federated spots, allow me to make posts that I would otherwise get faulted for if I tried them on Reddit. Like on AskReddit, they don’t like it when you ask a question and try to put something in the message body for clarification or it gets removed.
So you have to spend time making another comment to clarify with the possibility of it not being understood anyways because hey, hindsight users.
The karma system on the fediverse does not necessarily impact how much you can post and where you can post. Probably one of the big differences between Lemmy and Reddit for example. If you had negative karma on Reddit, good luck trying to post anywhere because you’ll get nagged with Captcha systems.
And good luck posting anywhere you’d like on different subreddits because they’ll just outright remove your posts automatically because an arbitrary karma count wasn’t met and no subreddit is transparent about it.
Preventing replies can done on some Fedivere apps (not Lemmy, yet, though, I guess). e.g.
As for your other points, they all sound like attempts at improving the quality of the conversation. They might not have been implemented well, but requiring a clarifying comment for a question, and blocking low-karma accounts aren’t bad ideas in themselves. Lemmy, etc don’t really deserve praise for not even trying to implement ideas like this at all.
(the benefits that others are mentioning in the comments have lots of validity, though, of course)