If you have an AWS account that for some reason you lost access to (losing access to the mail attached or to the second factor auth number) then you are lost.
In the site, they tell you to call their support number: 1-206-577-1364
But this number is not available.
And it seems like it isn't available for months at list, from searching the internet:
https://twitter.com/opethftw/status/1429019949377507329 (Aug 21', Amazon tells him to try again. This doesn't work)
https://www.reddit.com/r/amazonprime/comments/nzlqpl/customer_service_numbers_dont_work/ (Jun 21')
You might find yourself locked out of an account draining your bank, with no one helping you.