What Is the “Priority Fee” and Why Is It Still Necessary with EIP-1559?

The priority fee, or "tip," is an optional amount paid by the user directly to the validator who includes their transaction in a block. It is necessary to incentivize validators to prioritize a user's transaction, especially during periods of high demand or congestion.

Since the base fee is burned, the priority fee serves as the direct economic reward for the validator's service, ensuring block production remains profitable.