I feel like Civ5 had the right amount of dynamism. Friendships end when interests diverge. Ed Beach pulled off a pretty convincing inflection point system where you can reliably be friends for 30-100 turns most of the time (and of course there will be some Civs you can stay friendly to for much longer if both Civs don't really come to blows over borders or city states), but you know generally, won't last forever as eras change and the AI go for their VC or you fight over something or the other. That's really dynamic. Not to beat a deadhorse but my problem with Civ4 diplomacy was it was anything but dynamic. It's too stable. Was fine for the time, but after Civ5 it's hard to go back to AIs so easily manipulated with gold and switching to their desired religion and what not to appease them. Civ6 is curiously missing many of the stabilizing modifiers Ed added in Civ5. It's even missing the inflection points and ideological conflicts in Brave New World. So my feel is they are going in eventually and they probably ran out of time adding them. Still curious nonetheless since it seems like a no brainer to build on the Civ5 system and layer these transparent agendas on top, but I guess they really did rebuild everything from the ground up for Civ6 or else those features should have been easily carried over from 5.