It is interesting that one of the possible futures of the Internet -- PARC's NDN (Named Data Networking) -- resembles Plan 9's namespaces where the user is most interested in the name of the resource rather than where it resides (e.g. users/programs care about  /mnt/factotum or /n/sources rather than where it's imported from).

https://www.parc.com/content/attachments/named-data-networking.pdf