CK3 specifically leans heavier towards RP elements than most of our other Grand Strategy games do. It's easier to get into than the rest of the PDS catalog (due to how well it presents information, not because it's "simpler"; we got a lot better at explaining what the hell is going on to the player between CK2 and CK3), but it also provides an experience quite different from the rest of the catalog as well.
I'd say it's a good entry point to see if you like the broader gameplay style offered over traditional 4X games, but if you're coming from a Total War or Field of Glory background then you may get more enjoyment from titles like Europa Universalis, Victoria, or Hearts of Iron.