Changing Civ's wasn't really the issue, Humankind or whatever it was handled it well enough. The issue is that each stage is a new map with new units and shit, effectively splitting it into 4 smaller games.

Okay but have they made it accessible to new players? I've tried playing a few times and get bored because I'm not sure what I'm supposed to be doing.

Then is there a point in switching from 6?

I haven't been keeping up with Civ 7 developments... Is this saying that harbors, privateers, and ranged naval ships weren't in the game at launch? Wtf