i'm a plan 9 from bell labs fan. Imagine how excited I was when wsl used 9P for its plumbing. then they scrapped it all for wsl2.
just, the power they managed to get out of those union mounts... your application wants access to the mouse? sure, here's a file named "mouse". it's got the coordinates in it. you want to draw to the screen? here's a file called like "bitmap" or whatever, just write to it. you want to start a process on another machine? just cd to it and start the process there. want to have the UI show up on your machine? symlink your bitmap file to that directory.
I also wish early web composability could have stayed and expanded. like, the old vlc embed player, which would just show up in your browser and could play any file inline? great stuff. Imagine if every application composed with everything else, like the android Activity and Intent concepts but for anything, just by virtue of living in the same os. need an image? just ask the os and it will present the user with many ways to procure an image, let the selected one run , and hand you back an image. you don't even have to care where from.
in a way, it's what the arcan guy is doing with his experiments, although that's more for stitching together graphical pipelines.
They're "file like" in the sense that they're exposed as an fd, but they're not exposed via the filesystem at all (Unlike e.g. unix sockets), and the existing API is just mapped over the sockets one (i.e. write() instead of send(), read() instead of recv()). There's also a difference in how you create them, you open() a file, but connect() a socket, etc.
(As an aside, it turns out Bash has its own virtual file-based wrapper around sockets, so you can do things like cat a remote port with Bash, something you can do natively in Plan 9)
Really it just shows that "everything is a file" didn't stand up in practice, there's more stuff that needs special treatment than doesn't (e.g. Interacting with TTYs also has special APIs). It makes more sense to have a better dedicated API than a generic catch-all one.