Tbf, EU4 is basically a blobbing simulator at this point. The fact that people legit achieve World Conquests with the most ridiculous starts is a testament to it.
It would be cool to see CK2 go as far as 1800, while implementing colonisation mechanics and such
CK2 is the game where you can legitimately, passively conquer the world you see. My Gotland game for the achievement was only meant to encourage a reformed Germanic Europe from a Baltic centered Empire of Scandinavia. Despite only rarely declaring wars, largely to clean nearby borders, for centuries my vassals managed to conquer everything in the map except Mali, India, Tibet, and some surrounding central Asian lands. If I had attempted to expand myself, I would have easily conquered the map.
EU4 requires that you actually declare wars to expand to anywhere near that degree. Your subjects will never conquer most of the damn world of their own accord. CK2 is a blobbing simulator much more than EU4 solely because I don't need to act to blob.
In CK2 there is always the lingering risk of rebellious nobles that can actually dismantle you. In EU4 you just get Humanist ideas and are pretty fine for the most part. Not to mention the numerous freebies, like trading professionalism for manpower
I'm a modest CK2 player. Rebels are rarely a threat. Vassals are easily placated or hamstrung. With Jade Dragon and all other DLC, I had a world spanning empire made by my vassals and had no rebellion or rebel threats. I was easily able to cut off most threats with marriages or giving council positions. It is easy to get enough troops/levees to kill rebellion threat.