I have been using (not as admin, just member) various forums for years, but they generally looked the same.
There’s the index or front page listing all the subforums, or sometimes all forums grouped together by subforum.
When looking at the list of topics, you could see who started a topic and when, and who replied last and when they did.
When making a new topic, you were on a full page.
So far, Discourse is none of that.
Is that a problem?
Maybe not after you get used to it.
But I certainly had a moment of “what the hell is this I don’t like it already”