I run a ~75TB plex server with 99% on Google drive with 0 issues using rclone mount on a haswell i3. Can get close to 20 folks on gigabit before it blinks.
The only Google Workspace plan that offers unlimited is the contact-sales-for-pricing "Enterprise" tier. The $12/user/month plan only includes 2TB/user: https://workspace.google.com/pricing.html
Holy shit. I didn't know that was an option. I just assumed that there was some minimum number of users (like 10-20) that made it non-viable for personal use-cases.