Thanks for your reply.

That is a possibility, I might be naive but I consider it on the very unlikely side. What I would imagine in that case is that I would reset the important other accounts such as the bank ones by showing up in some physical office with my passport, or something similar, while waiting to solve the situation with Google.

What alternatives would you suggest? Spreading the accounts over different email addresses? Letting aside the privacy issue, to be honest I don't think there is another mail provider that I'd trust better than Google from a security point of view.