Because CD rom cartridges arent made anymore (at least i think) plus as i said before. Nobody else other than a few people on the wiki like me and @GAME043010 care about lost world. So maybe its just cus they arent made.
but is it official? I have seen games similar to that, (generations and sa2) in that format but I don't know if they are official, (I myself have a copy of adventure 2) its origin intrigues me a lot