What might finally shake out is not that a crypto is directly used for payment settlement but rather it serves as the foundation for a settlement layer. For example, you pay for things using a credit card but you eventually pay off that credit card with money from your bank account. Until then, it's just a number on VISA's balance sheet.

There are a number of startups already trying to capitalize this, issuing credit cards where you don't pay directly with the token but use tokens to settle balances on at a much more leisurely pace. Thus far, very few blockchains can run at 10k+/sec transaction speed that live payments would require.