The problem with the RBE is that the resources on Earth are finite. So you must put a value on them and a money system is necessary. A better idea is the transfer of the file sharing model to the monetary system. You can share the coins like files, through a p2p network.
...but why put value on the Earth's physical resources?
Because the Earth's physical resources are not infinite. RBE is impossible in a finite world. Only air and water are abundant so these ones are free or very cheap. The best thing we can do is to share the money fairly through a p2p network.
You are making a tautological and arbitrary argument by saying air and water are cheap because they are abundant.
Land is abundant, but it is not free or cheap. All the world's resources are manageable to provide optimum benefits without wasting them on planned obsolescence and war. It will require unlearning conspicuous consumption and privatized capitalism.
Fair money helps people sort out these priorities because people give the money its value, not the other way around. Fiat money gives human life monetary value and enslaves them through inflation. This is the lesson Bitcoin will teach the world about who we are in relation to our world.