What are the main criticisms with the newer games?

As per title. I’m looking for some more Assassins Creed games after having platinumed Black Flag Resynced,but having a scroll through the subreddit I can see there’s debate on what’s worth buying/playing.

I’ve played the original AC:BF, Rogue, and a little bit of Valhalla. I own syndicate but have not put more than an hour into it at launch.

I’m looking primarily at Unity and onwards.

Valhalla worth getting into? Syndicate? Or is there a newer entry that’s well worth the price.