Yes, not all accounts will revolve and be charged interest, many will. credit card balances have been going up for decades: https://fred.stlouisfed.org/series/REVOLSL (This is ALL revolving credit, not only credit cards, but it's mostly credit cards). It's well over 1 trillion dollars now. Yes there are cost(s), but credit is a very strong and well run business now and is absolutely a profit center for banks. If they get too many freeloaders that don't carry balances to hit their income targets, they will add some fine print to curtail freeloader use-cases enough that they can hit their income targets. This has been going on for decades now.
For me, because the RH CEO in an interview (https://www.youtube.com/watch?v=QT5OMUdaZtg) said he wanted the card to be profitable on a standalone basis, I just don't see it that way, but you can be right for all I know.
I got one part, at least it seems, wrong in my blog, that was my bad. I just want to say I did not forget about the interest income side of the card, I just don't think it will be profitable. Again I can be wrong. But thanks for the interaction.
Yes, APR is going to be 20%+ and even 30%+, but not all cardholders will revolve. Some, if not many, will be transactors and won't pay any interest at all. There is also cost of funds and losses. There is a reason why there is no other 3% cash back card on the market. The most popular set-and-forget card out there is 2% cash back.