I was always bemused about this idea that putting multiple credit cards on a single physical card is some great feature that a lot of people want and would pay money for.
In my experience, having many credit cards is a complete pain to manage, because for each card you need to monitor the statement, set up the automatic payment (or do it manually), change the address when you move, etc, etc, and no sane person is going to want to do that for lots of cards. The fact that it also fills you your wallet is really the least of the problems you'll have.
It's nice to have one card as a backup, and some hardcore churners / points collectors are going to want 5 or 6 cards and use different cards for different categories... but they're real niches, it's not something that a mainstream, mass market consumer is going to want to manage.
In my experience, having many credit cards is a complete pain to manage, because for each card you need to monitor the statement, set up the automatic payment (or do it manually), change the address when you move, etc, etc, and no sane person is going to want to do that for lots of cards. The fact that it also fills you your wallet is really the least of the problems you'll have.
It's nice to have one card as a backup, and some hardcore churners / points collectors are going to want 5 or 6 cards and use different cards for different categories... but they're real niches, it's not something that a mainstream, mass market consumer is going to want to manage.