There were 3 catacombs while the map was 3k*3k,which means 1 catacomb in an area of 3million m².Nowadays we got a map of 30k*30k whilst having 10 catas(some not even active),which means only 1 catacomb(best case) in an area of 90million m²...
There are 7, not 10, and they are all active(idk what an inactive cata even means), so you were correct that they are more rare, but you were once again just making stuff up