Which is why we have abstraction layers like Samba (etc) on top of networked drives. They're descendants of vintage cross-OS utilities like PIP which provide a minimal interface that supports folder trees and basic file operations.
But a lot of OS-specific options remain OS-specific, and there's literally no way to design a globally compatible file system that implements them all.
This isn't to say a common standard is impossible, but defining its features would be a huge battle. And including next-gen options - from more effective security and permissions, to content database support, to some form of literally global file ID system, to smart versioning - would be even more of a challenge.
The actual path of file in Windows can be practically unlimited, but either requires using special network notation that can exceed 256 characters or relative addresses. Recent versions of Windows includes a setting that removes the limitation in the APIs because of development issues like node nested packages.
Many reasons, the most important being patents and insistence by vendors to keep stuff proprietary (exfat, ntfs, HFS, ZFS).
Also, there are fundamental differences on the OS level:
- how users are handled: Unices generally use numerical UID/GID while Windows uses GUIDs
- Windows has/had a 255-char maximum length of the total path of a file
- Unices have the octal mode set for permissions, old Windows had for bits (write protected, archived, system, hidden) and that's it
- Windows, Linux and OS X have fundamentally different capabilities for ACLs - a cross platform filesystem needs to handle all of them and that in a sane way
- don't get me started on the mess of advanced fs features (sparse files, transparent compression, immutability of files, transparent encryption, checksums, snapshots, journals)
- Exotic stuff like OS X and NTFS additional metadata streams that doesn't even have representation ín Linux or most/all BSDs
And finally, embedded devices and bootloaders. Give me a can of beer and a couple weeks and I'll probably be able to hack together a FAT implementation from scratch. Everything else? No f...in' way. Stuff like journals is too advanced to handle in small embedded devices. The list goes on and on.