Whilst this is more about AWS accounts, the ability of Amazon (and other cloud providers) to lock you out of an account with very limited recourse does present some other problems.

I've got quite a few ebooks I've bought via Amazon Kindle. If amazon one day decided to delete/lock my account, I would lose access to all that content which I had "bought".

The more data people store in various cloud providers systems, the more the need for some kind of recovery mechanism / dispute resolution process becomes apparent.

Whilst its relatively easy, in many cases, for more technical users to ensure they have backups of data that they control, less technical users could have a lot of their information tied up in these systems, and loss of it could be quite bad for them.