* For individual banks and their customers, is it more likely that an AWS-wide exploit will compromise an AWS-hosted bank, or is it more likely that a self-hosting-specific exploit will compromise a self-hosted bank?
* For society, is it better that security efforts are concentrated in on centralised providers like AWS, or is it better that security efforts are distributed, on individual hosting entities?
>That's more or less the same question as "what if the data center/servers operated by the bank gets compromised".
The difference is that cloud relies on public services, which once compromised (e.g. via social engineering), allow for lateral attacks resulting in much bigger impact (e.g. Lapsus$) across the complete customer base. This makes social engineering much more attractive in cost vs impact. The resulting monoculture in not only the software, but the infrastructure and configuation also increase the impact on technical attacks on specific exploits.
* For individual banks and their customers, is it more likely that an AWS-wide exploit will compromise an AWS-hosted bank, or is it more likely that a self-hosting-specific exploit will compromise a self-hosted bank?
* For society, is it better that security efforts are concentrated in on centralised providers like AWS, or is it better that security efforts are distributed, on individual hosting entities?