File Providers are useful in some scenarios, but they are also not really a FUSE equivalent.
They're more geared towards Dropbox-like synchronizing use cases. Some developers have made it work for SSHFS too, but even that's already a bit of a stretch; for more custom solutions it definitely falls short: https://developer.apple.com/forums/thread/681325
The only option currently seems to be to implement a network file server such as SMB (which is what Google Drive used to do before File Providers existed!) or NFS, for which there even is a FUSE bridge available: https://github.com/macos-fuse-t/fuse-t
They're more geared towards Dropbox-like synchronizing use cases. Some developers have made it work for SSHFS too, but even that's already a bit of a stretch; for more custom solutions it definitely falls short: https://developer.apple.com/forums/thread/681325
The only option currently seems to be to implement a network file server such as SMB (which is what Google Drive used to do before File Providers existed!) or NFS, for which there even is a FUSE bridge available: https://github.com/macos-fuse-t/fuse-t