Twitter does have its neat points: kind of following multiple "blogs" at once"; also first-class comments (a reply is also a Tweet, easily shareable, providing a virality that can be good or bad.

I mean, all of that is entirely true of Mastodon as well. The biggest difference is mostly that Mastodon tends to lightly dampen virality rather than AI-amplify it, very deliberately. That means that you don't have the rage-machine effect of the big sites, but also means that it is weaker for things like calls to collective action.