The farm APR is linear and prints 24/7, regardless of HERMES's relation to the peg. OLYMPUS, on the other hand, prints only when HERMES's TWAP is above 1.01. Therefore, it may not always be that an investor gets a higher return from the OLYMPUS than from the HERMES-AVAX pool.
Because $HERMES follows the price of $AVAX, the HERMES-AVAX LP is akin to holding $AVAX in your wallet, except with the bonus of a high farming APR on top of it. In other words, if you're bullish on $AVAX’s price action, the HERMES-AVAX LP is a way of holding exposure to that single asset while also reaping high APRs.