Well, what if it's a separate directory meant exclusively for remote systems alone? And what if the remote mount is read-only, perhaps with a writable layer on top using overlayfs that can be discarded on logout?
It's actually far less complex than what container runtimes do. I've even done parts of those, which is why I'm able to suggest it. I'm thinking about implementing it and was checking if anybody else wanted to do it or if they foresee any problems that I can't.