Earlier quoted context omitted.
Depends on your points usage, airline points can be much more valuable than the 3% fee.
On average they’re worth much less. After all, why would airlines cross-subsidize a card on which they earn <3%?
Why subsidize? There is no subsidize at all, an empty seat on a flight is an empty seat unsold, any money they can make back is extra profit. Airlines do not make money by flying people nowadays, but by selling miles in bulk to banks [0].