[2023] Elevate the Kingdom of Mann and The Isles is a downgrade?

Originally posted by kalanyr: There comes a point when the advantages from Tribal fall off in comparison to the Development bonus and Innovations (and thus better buildings) you get as a non-Tribals.

This will probably happen somewhere between 1000 and 1100 but by the time you start to feel the effects bite, you're going to be far enough behind that it's hard to catch up.

I mostly recommend you Feudalize when you've expanded as far as you can with Confederate Partition and have reached the point where the only thing blocking Early Medieval is the Culture Head being Tribal.

Seconding this; Tribal is incredibly powerful in the earlier years, but it falls off rapidly once post-tribal cultures start to really get their tech going. By the end of the game, Tribals are almost entirely toothless, with feudal armies able to stackwipe tribal armies 10x their size with ease.