It’s not a network file system. It’s a regular file system for hard drives, SSDs and such, which is used by default on Windows since Windows NT (that’s where the NT comes from - it doesn’t stand for network but “new technology”).

The implementation in Windows is closed source meaning the file system had to be reverse engineered to even work at all under Linux. Support nowadays is okay-ish, but as soon as you don’t properly shutdown your computer or use the file system under Windows, you will run into weird problems.

Also it just straight up doesn’t work for most games running under wine.