If the problem of secure, non-wasteful, convenient, easy to use, programmable and distributed ledger problem is solved once ... how will coin X be different from coin Y? Especially if you can exchange X for Y and Y for X... They will all increase the usable "coin" supply without any singular chain having the means to do anything about it. From there, the scarcity argument goes out the window and becomes an academic exercise (...if we had an isolated single blockchain, this would apply type arguments).