No we don’t need to pay billions. There are moves afoot in the UK to do direct bank to bank payments with Open Banking. HMRC (the UK tax authority) has been doing this for years. When I pay my tax bill, I select my bank, scan a QR code with my phone, that launches my banking app, I authorise the payment and off it goes in just a few seconds. Instant and a few pence, even for thousands of pounds. This particular implementation is provided by Ecospend but there are a few other companies offering this same service now in the UK.
I agree with the OP, Visa and MC charging so much is just insane when you think about it. It’s more expensive AND settlement times are days, not seconds. The only barrier is consumer awareness and detrimental UK legislation forbidding card fees to be added to bills which while well intentioned completely ruins any competition on payment methods.