The whole value comparison thing is weird because rules are not always made to gain net positive value. Because if they did then stuff like Universal healthcare will never happen.
Secondly, businesses are a complex beast. It's not a simple debit/credit and there are tons of different schedules which run simultaneously. It is easy to get lost - whether it is customer's or the business' own money. So, every business run audits and reviews. Banks more so because they have other people's money. The only difference is whether they have legally mandated to share the findings and take corrective action.
I don't disagree with you - I just wanted to point out that "see this caught 300m$ error therefore it's worth it, and it also validates other regulations" (which is how I read OP and a common line of reasoning I see in public debates) is dangerously wrong because it ignores costs completely.
Secondly, businesses are a complex beast. It's not a simple debit/credit and there are tons of different schedules which run simultaneously. It is easy to get lost - whether it is customer's or the business' own money. So, every business run audits and reviews. Banks more so because they have other people's money. The only difference is whether they have legally mandated to share the findings and take corrective action.