I think "no one" is a fairly tall claim: They are well-used on all the operating systems that do support them.
Mind also, "old POSIX ACLs" came from a POSIX draft: they never made it into POSIX. While being an extremely simple expansion of the Unix modes, they are only ever additive and do not support fine-grained permissions that NFSv4 allows for. They're sometimes better than the standard mode bits, but they very often come up short of being useful in the real world.
Mind also, "old POSIX ACLs" came from a POSIX draft: they never made it into POSIX. While being an extremely simple expansion of the Unix modes, they are only ever additive and do not support fine-grained permissions that NFSv4 allows for. They're sometimes better than the standard mode bits, but they very often come up short of being useful in the real world.