Are we sure there is an actual data loss event, now? Has anyone here experienced the loss directly from Google Drive?

My guess would be they have multiple backups. I obviously can't say for sure since I don't work there, but it's very very good guess.

Right but this doesn't necessarily have to be a drive failure. (Pun not intended.) Imagine if there was some id collision due to a db migration or something, and then one user ends up deleting the other user's data accross all backups. Unless google never deletes any data, even when the user deletes it themselves, then you can't be saved from that.

Theoretically possible, but (super super super) unlikely. I'd also think that when a user "permanently" deletes their data, it would still be on Google servers for a specified time (maybe a week?).

Again, all guesses. But if someone offered me a bet, I'd wager 1:10,000 that the data is permanently deleted. Extremely unlikely.

30 days has become the industry wide standard for keeping data explicitly deleted by a user.

There are many types of backups (e.g. replication, point-in-time replication, periodic incremental backups, periodic full backups) and not all of them project against the worst kind of issues, e.g. a software bug that accidentally deletes a whole bunch of data.

For Gmail, Google keeps backups of mail boxes and their transaction log. This way they can rewind the mailbox over a period of weeks.

It's basically a continuous backup.