Basically, the traditional financial services partners who give startups access to these legacy networks know their clients are startups who might not fully understand the space or might want to cut corners. They're good at making sure they're protected against their clients' behavior, and in most cases legally the end users are actually the customer of the financial services company, the startup will be considered a "deposit broker" instead of a "bank" etc. Its been longer since I've touched the stock broker side so I'm fuzzy on the specific terminology but its similar there.
Traditional finance is secure for a reason! Good they have strong requirements.
Seems to still require manual work, though? With less than 30 days to do so...