Two businesses can sell the exact same product and carry completely different legal, tax, and chargeback exposure, depending entirely on whether they process through a Merchant of Record or a standard merchant account.
The password screen you remember hating during checkout is mostly gone. 3DS2 passes over 100 data points to the issuer, reaching 85-95 percent approval rates versus 60-70 percent under the old protocol, plus a real fraud liability shift.