Any fintech (and these can afford smart people) is building with defense in depth, encrypting everything with their own keys, using ephemeral credentials (eg issued by hashicorp vault), etc, etc.

You're seemingly applying your own experience with cloud-based storage, like Dropbox, to the enterprise cloud-based infrastructure.

I don't feel like I should spend any time laying out my professional experience with these environments, I guess you could just skim through one of the books and watch a couple hours long video explaining layers of the leading "cloud" offerings.

And yes, eventually the breach will happen. Like it happens on premise all the time. 2014 Sony and 2020 Solar Winds are good examples.

Let's agree to disagree, I really don't want to spend any more time on this, I know how a good solution (passing multiple audits and pentests) looks like, you however have your opinion. I'm not going to fight you :)

Take care!