
Prepaying for state access is deliberately cheaper than touching it cold. EIP-8038, scheduled for Glamsterdam, prices an access list address at 2,900 gas and a storage key at 2,000, against 3,000 and 2,100 for the same cold access. The gap is exactly WARM_ACCESS, 100 gas, subtracted because the entry is already warm when the transaction reaches it. Without that subtraction, declaring in advance would cost more than not declaring.
