I had a similar idea with aws nfs as a service, never tried it but expecting similar results.
Notably, Google Drive does not allow you to partially modify a file: you can only do whole replacement (similar to s3).
Practically, using a nbd (Network Block Device) is going to be a more direct way to accomplish this goal.
Ouch. Now I can’t stop thinking about marrying shmget() with dropbox for the ultimate in low-performance high-performance IPC.
I ended up doing a similar thing but over s3 and s3fs.
The only practical use case I tried using this is for “overflow swap” to delay oom killings.