Earlier quoted context omitted.
The hard part is convincing anyone to use your open protocol, when the people who are in the best position to implement it are also the ones who would most benefit from a closed-protocol.
Bitcoin used to do this: low value and/or infrequent transfers used to be free. Only charged money for big transfers and the high frequency traders. Dunno why it stopped. Seemed sensible to reward hodlers and incentivize use for microtransactions. Ultimately, liquidity comes from being able to trade a big thing easily for lots of small things.
Miners used to include zero-fee transactions in blocks when there was space available. Nowadays, most blocks are full or nearly so, so miners have a financial interest in mining transactions with the highest fee-per-byte first and ignoring anything which has a low or zero fee attached.
There was never any special handling for "infrequent" transfers.