The original poster is right. Blockchain solves distributed trust. Scarcity is a particular rule, and blockchain is solving a problem of trust in that everyone

The original poster is right. Blockchain solves distributed trust. Scarcity is a particular rule, and blockchain is solving a problem of trust in that everyone are obeying that rule. You can have a blockchain that enforces completely different rules, where scarcity don't matter. And you can have scarcity in a system where trust is not a problem (trusted central party).