The only thing I can think of is because certain issuers/networks treat Card Not Present transactions differently for chargeback disputes. For example, depending on the network, if you fail to collect CVV or zip code, you automatically lose second presentment rights. I don’t know how CNP vs CP charges are priced, but the mere presence of different fraud liability treatment leads me to believe there’s a fundamentally different lens applied to online transactions, and real life (less likely to be fraud?) transactions.

Just my guess