Well, "in search" isn't quite accurate. I used creative mode on a copy of the world to find one then went to the coordinates in survival. There was actually one a couple hundred blocks away but it was WAY too small and it was in an inconvenient spot
I just went a few thousand blocks away from my base in search of a swamp and I refuse to go back until I've built a slime farm... But ironically I don't wanna build the slime farm