Typically dumb pipe companies get involved in this side of things due to legal requirements. Less often, though often justified as such, it is due to sincere concerns by the provider.

For example, banks don't typically want to service car dealerships simply because they are a prime target for money laundering. Same for legal cannabis firms due to being unbanked previously or because the whole industry isn't traceable.

Frankly, while I understand the historical reasons for having a "big brother" watch financial transactions, it's way to convoluted to satisfy and represents a big cost in the economy.