I wonder how OP will end up handling a gas station chain named after a certain type of quotation mark asking him to enter the CVV on the terminal. Especially if his car has almost no gas left and his card won't work at the pump for whatever reason.

(This exact thing happened to me this morning. Well, not the nearly running out of gas or the card not working outside, but the terminal inside did ask for it.)

Anyway, the physical store locations ask for it because they had to manually enter your card details for whatever reason--or their terminals don't have chip enabled and it's an additional security measure. Online stores ask for it because it shaves a bit off their card fees and is something that in theory only the cardholder would know, as it's supposed to be disposed of by the merchant after authorization. Really, we should do 2FA for online transactions but I imagine US stores/issuers aren't going to bother if we're going so far as to effectively get rid of all cardholder authentication for chip transactions.