My guess is that inotify is so slow with large directories that it wasn't worth it. Plus inotify has cumbersome user limits. inotify has a number of other rele

My guess is that inotify is so slow with large directories that it wasn't worth it. Plus inotify has cumbersome user limits. inotify has a number of other relevant limitations, like not being able to create recursive notifications or handle "move" operations. Implementation effort is going to be way higher for an inotify-based system, and of course that's made far worse by the numerous file systems in linux - I imagine any implementation would probably start first with ext4. I suspect an ideal solution would be via ebpf, but I'm not sure.