I bought the original CK pretty much on release, but I didn't get CKII until 2016. I had a lot of fun with the original even though on balance, it was really pretty much a broken game--there were large areas of gameplay that never worked as intended, but, typically of Paradox products, it did get a lot better when patched. Had there been a couple of more patches/expansions, I would have probably been more willing to buy CKII sooner; I felt like Paradox had abandoned CK before getting from being a good but flawed game to a state where it was a great game. That, and a couple of other disappointments, got me to a point where I wasn't willing to give new Paradox games a chance anymore. Fortunately, someone finally convinced me to give CKII a try, and I bought it on sale. I'm glad I did, but I'm also glad I didn't get it right away, because had I done so, I probably would have abandoned it after a couple of attempts, given what I've heard of its initial state.Yeah, it's funny. I bough the original Crusader Kings when CK2 was already in the works. Played it for years. When I finally got bored with it, moved on to other things instead of CK2.
After many years, I finally came back and bought CK2, only to find CK3 already in the works. Deja vu!
I've still got lots of things to do in CK2 that I haven't tried. Lots of playing time left! When I get bored with it, I'll probably turn to other things rather than CK3.
I'll probably come back and buy CK3 just in time for them to release CK4!
There are still a few things I think the original did better than CKII--for example, whereas in CKII, sieges always progress at a set amount every 12 days, siege progress was somewhat random in the original--but overall CKII is a far better game.