How Do High Gas Fees Facilitate Front-Running in a Proof-of-Work or Proof-of-Stake System?

High gas fees facilitate front-running because block producers typically prioritize transactions that offer the highest fees, maximizing their profit. Front-running bots exploit this by observing a profitable transaction in the mempool and submitting their own order with a significantly higher gas fee (a "priority fee" or "tip").

This ensures their transaction is included in the block before the target transaction, allowing them to capture the arbitrage opportunity.