virtual card #s is a great system, why did it rot?

I assume it's because the whole industry prefers data-brokering your purchase history, joined on credit-card # to establish identity.

That's one good reason, another is probably pushback from merchants. Having these virtual cards completely shuts down the "free-trial-we-hope-you'll-forget-and-let-us-ding-you-for-a-month-or-two" business model that's so popular for online services.

Not sure you need merchant pushback there - if it leads to unexpected charges then it's more likely to lead to inability to pay, or short payment, which gives the credit card companies their chance to feed off the client.

Also usability, most people just don't care enough. (which is reasonable often)

Wouldn't the bank still know your full purchase history (since they know what numbers are tied to you)? So they'd in fact get a leg up on the competition, who get a more distorted view?

But they don’t get the invoices of what you bought, just the total payment amount.

Unless they work with an analytics system that mastercard, visa & amex participate in to link card numbers to invoices for better advertising & affiliate data.

I know FB & Google purchase something like that from one or two credit card companies, so I wouldn't be surprised if merchants were in to it too.