Banks tend not to over engineer things. KYC can be seen as a 3 sided trade off: cost of KYC infra/process/etc, lost revenue from denied business and fines from regulators.
They (the banks) don’t really care about the social goals of KYC, they just try to best optimize for expected value in the trade offs.
The regulators understand this, and are basically fine with it. They have their own trade offs they are balancing.
Both sides mostly find and equilibrium.