Seems to me like EF is the only mount that has widespread adoption on all platforms, beyond that there is usually just adapters that are made for the same brand, Sony A (Minolta) to E mount, Nikon F to Z etc. Nikon does also allow for the contemporary E mount to be adapted so should in theory be able to use A mount lenses.
Isn't there any interest in or enough of a market to make other DSLR lenses available for other mounts?