https://primal.net/e/note1ss06qph96theqe249qflx5kmg9pr4yhzegmn293eetlj7zt0dfeqdfsc5l
You are not getting incentive structure of the spam. They don't care about exchanging value. They care about gambling and speculation.
When purpose and incentives are totally different, you can't say that high fees will kill spam.