This summary is really to the point portent88[B]

Especially the lacking AI in the late game (plus the micromanagement later on) makes the end-game rather chore.

I currently tend to start new campaigns with varying factions and difficulty levels to see if I can survive the first 150-200 years only - and if I get past this period I call it quits (although I might miss some interesting twists during the campaign that way)

Hopefully CA is able to improve on some of the points you made (maybe already in Viking Invasion?)