Removing the middlemen is the most obvious solution, but they’re also amongst the most powerful players in the world, so it’s going to be challenging (to put it mildly).
In some places it’s already more than viable. In Europe it’s baked into the banking system, SCT (SEPA Credit Transfer) lets you move money between any two European accounts with only as much hassle as your bank wants in your way. And EPC QR lets you initiate transfers from QR codes.
The biggest annoyance with it is that uptake is quite variable from country to country.
In the Netherlands we have bank cards and IDeal for offline and online payments respectively. Those answer to local legislation, and do direct bank-to-bank transfers.
But if I want to buy online from Germany or some other EU country, I need to use American payment method. Also if I want to buy from China, I need to use an American payment method.
Part of the problem is that you have to make a clean break from these middlemen. Steam can't say "for these games, we only take this form of payment", it's either only sell games Visa and MasterCard say you can, or no one can pay with their credit cards.
See: https://www.taler.net/en/index.html