Well they want to prove who you are because a Google account is the central part of someone’s online life. I’d imagine that binning off all that info quickly looked really suspicious and flagged something on their systems. They can’t just let that slide because of the possible implications, someone might use that email as their bank account login or maybe it’s linked to something really personal.

Is it out of the goodness of their hearts? Hell no, it’s entirely to cover their asses from liability for damages.