The impact of the Cancun upgrade, the main reason for the gas reduction on the second layer is two parts: the first part is the introduction of blob in eip4844, abandoning Calldata. Blob storage costs less and provides more space. Empty every 30 days. There is also eip1153, which adds instant memory. You can think of it as flash memory in a computer. These two upgrades increase the speed of the second layer and reduce the gas of the second layer.