A few notes to those who are not familiar with how Bitcoin works: 1. If you think tx A appeared before B, that's not necessarily the order a particular miner s

A few notes to those who are not familiar with how Bitcoin works: 1. If you think tx A appeared before B, that's not necessarily the order a particular miner saw them. The whole point of the mining is to agree on order. 2. That said, a minute or two difference is pretty universally visible, so it's reasonable to ask to prioritize the first-seen transaction. However, from the user's perspective, transaction is going to be confirmed within tens of minutes, or even an hour or two, so a shorter difference in time between your transaction and mine is no more important than ordinary variance in block times. 3. When the mempool is full, the entirely "capitalistic" relay logic exhibits some "socialistic" properties: a newly coming transaction has to cover for the lowest-paying transaction that is going to be kicked out. This is a necessary anti-DoS measure to prevent flooding the network cheaply with transactions that kick each other out and most of them end up non-mined with disproportionally low cost of mining the rest. In other words "if you kick out a tx, you have to pay for it, because it was previously relayed". This means that later coming, higher-paying transactions can't just take a seat paying marginally higher fee. That margin is going to continuously escalate as the mempool is being overloaded, better protecting transactions that were already relayed. 4. Finally, mining is very competitive. If you don't prioritize by feerate, another miner will and their extra profit would allow for capturing higher percentage of the hashrate while growing difficulty makes it even more expensive for everyone else. Any sort of agreement that undermines everyone's profits in the name of fairness requires (1) establishing a consensus in the first place, and (2) keeping it relatively static so random outsiders don't undercut it. But then such organization can use its leverage against outsiders in order to do many more things: censor transactions and change rules. That's why Bitcoin works the way it is: so anyone can join and mine without permission, funded by leftover profits, so no single miner (or group of miners) has no long-term leverage against everyone else.