Incomplete distinction:

For institutions, stables are primarily a messaging protocol innovation, like ACH or SWIFT, but where the 'medium is the message' -- both the state change and trusted, instant settlement (the key innovation of blockchains) vs. legacy systems where the message and settlement are independent processes.

For consumers, stables are primarily an innovation in convenience and economics/incentives. They combine the potential for rewards and better economics with the convenience of instant global financial access (still being built out)