Well at least with phone tap there's like a limit of $200, so maybe some company can corner a niche market where they only cover small daily purchases. No $10,000 credit balances or $2000 purchases and points and whatnot, just like $1000 balance limits and max $200 on purchases through tap.

You wouldn't need quite as much capital that way, and I bet that would eat a good chunk of business from visa and MasterCard.

It's a catch 22. You need a phenomenal amount of capital to stand up a payment network with all those criteria, but anyone with that amount of capital can't actually be trusted not to abuse their position in exactly the same way the existing banking networks have.