Misskey and its forks are a bit in between and already very different from Mastodon. And I don’t think they bear any resemblance to Twitter (which I don’t know from experience). There are 3000+ characters and the thread display is also a bit better there and not quite as jumbled as on Mastodon. In my opinion, the thread view is best in Friendica (apart from Lemmy).
That’s true, the -keys are certainly closer to Twitter than to Lemmy / Reddit.
But even Mastodon can follow hashtags, the interesting thing about the -keys are imho the Antennas / Newspicker, with which you can set up individual timelines with your own search word combination. This makes it less user-centred and more related to topics / content. And at least you can display ‘load conversations to replies’ in the timeline (in Sharkey). This means that the post snippets are not displayed without context, as is the case with Mastodon, but a part of the thread is shown in the timeline.
As a result, threads from Lemmy are also displayed somewhat better in Sharkey than in Mastodon, where all replies arrive separately.