Some might see Occham's razor in this, but I could imagine this being a real edge case:

When I had an Android (OnePlus) device I often factory reset when tinkering with it, go to bed and continue whatever I wanted to do on the next day. Of course my phone had it's bootloader unlocked and TWRP recovery, since I was trying to get lineageOS + spoofed signatures + microG to work.

So basically the scenario is: factory reset your phone, go to bed, wake up with banned google account, have a new brick decor for your garden.

Would be funny if they didn't think of this possibility.

So, you're supposed to avoid doing factory reset on a phone once your account is banned? Sounds like an essential feature being held hostage.