You're going to have to give us more information than this. Sure, lots of business models "prey on poor people", but which ones of those are threatened by electronic wallets?

Lots of poor people do not have bank accounts, so there's no way they can use electronic only systems.

Electronic only systems like M-Pesa can replace banks.

https://en.wikipedia.org/wiki/M-Pesa

Not true, you can load money on a smart card via kiosk. This is already available almost everywhere, although would need to be accepted at POS.

Payday loan sharks are the big one. Universal banking puts them out of business.

Depending on what that phrase "universal banking" entails, sure. It is the case that some good loans are not being made because of the perceived risks of particular potential borrowers. I don't think free electronic wallets are going to help with that, however. Lots of bad loans are also avoided due to the perceived risk of the potential borrowers. An electronic wallet isn't going to help differentiate this.