I love these kinds of hacks. I can't remember how exactly it worked, but I remember a program or maybe browser extension from back before Google Drive existed that used Gmail's then-generous email storage space to store files.
FUSE let Linux do all kinds of interesting things. Forgot about this one, thanks!
[1] DSLreports discussion from 2004 https://www.dslreports.com/forum/r11192502-GmailFS
Once the cloud storage companies launched and provided free/cheap tiers for huge storage we mostly lost the need for it.
I still have emails that I uploaded with it. Need to sit-down and look how that extension worked