Agreed, the barrier for entry for a lay user is much too high, lots of terms and functionality gets thrown at you right out the gate. Hopefully the onboarding experience can improve with time.

Not as any sort of domino effect, those sites won’t know it’s invalid and even if they get bounced emails most wont have an automated process to close the accounts, and certainly not delete them.

It will just obviously make it even harder to get back into them, or easier if google opens up that email as registerable now?

This is really cool, thank you for writing this up!