The "value" is the payment network itself (plus stupid things like rewards which are taken from the businesses and distributed to the consumers). However, the payment network can easily be superseded by the internet, and all that's really needed is to build a ledger on top of it (and using something like PoS it could use an amount of energy probably on par with Visa, or at least comparable to it for the same number of transactions).

I mean, it's at least not "easily"... I'm sure in 5 or 10 years looking back it might seem easy, but looking back over the past 5 or 10 years it doesn't seem like it's easy.