That makes no sense. You can filter them out of your feed pretty easily, but they'll still be able to interact with you and of course bring a lot of new toxic users to you. Your browser can't do anything about that, it's entirely Twitter's side.
Looks like that's basically what's happening now that I looked into it more. Like I believe the "hide" user button is the same (idk I haven't been on the site forever lol), and the block basically blocks interaction but doesn't hide it. Honestly makes sense because you could see the user who blocked you if you simply clicked a thread link in private browsing.
Like if you replied and blocked me on Lemmy, I could still open the thread in incognito or whatever and see the whole public thread but not reply to you. Seems actually reasonable tbh, since the blocker and block-ee doesn't lose or gain anything they couldn't already do already.
That's how Reddit used to work until they made the idiotic change (IMO) to go the other way. A blockee loses the ability to even participate in any thread/post started by the blocker.
For example, after the change if I blocked you now, you wouldn't be able to respond to me or anyone else further down a thread I started.
This is a boon to bullshitters, disinformation campaigns, etc since those people could just post their bullshit and then block anyone who attempted to call them out.