Sort of! For starters, Discourse, Flarum & Vanilla all share a similar structure of a single feed of posts organised by tags which is quite different to an "old style" forum where there are individual boards. These kinds of set-ups are possible in those ones but aren't highlighted as much. But not only that...

Flarum is not at v1 yet and isn't really recommended for production. It's also quite feature light and I would be hesitant to expand upon it while it's not stable yet.

I've never seen a Discourse forum that doesn't look like another Discourse forum, have you? They all look the same! I had a pre-launch landing page up where something like 75% was on desktop. Discourse seems to have a mobile first, desktop never approach to its design and appears to be difficult to customise. I felt it was a sub-optimal experience suited better to communities centered around a single topic or perhaps support.

Vanilla is the most mature of these new style options but just wasn't doing it for me.

I don't think going a bit "retro" is a bad thing. I thought XenForo had a great balance between retaining that classic, nostalgic, familiar vibe while still providing lots of nice QoL features to go with it.