LOL, all fintech are using or entering the "cloud" very heavily. Cloud is here for long enough that claiming it's insecure shows only the immense ignorance.
Any business using commercial inference providers is potentially risking their value proposition. Everything you send to cloud inference will eventually be gleaned for training data.
Empirically we know that the data is the most valuable input to cloud services, and eventually it will be used, regardless of the user agreement. When the stored data becomes worth more than the company, it will be eaten and stripped by vulture capital. Law of the jungle, baby.
Just one of the later examples of a very long list of cloud data breaches affecting millions of users. But hey who cares as long as it does not affect your own bottom line.
This has affected login data and yeah, it's famously oracle.
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 :)
Empirically we know that the data is the most valuable input to cloud services, and eventually it will be used, regardless of the user agreement. When the stored data becomes worth more than the company, it will be eaten and stripped by vulture capital. Law of the jungle, baby.