Yea idk why people just forgot you can absolutely accept 0 confirmationation with like 99.99% assurance that once a txn is broadcast, it will come through eventually. (I wonder how many 9s it really is) Like as a merchant you can disctate a minimum on chain fee and accept 0 conf. That's an "instant" transaction as much as lightning is imho. If they paid standard fee, it'll settle before close of business day anyways...