Payday loans are often 300-600%. Or at least were in many states before regulation was passed. See here for details state by state:

https://paydayloaninfo.org/state-information

That said, APR of 20%+ on high reward credit cards is not uncommon. I have various cards with various APRs over 20%. I have never paid a penny of interest on them so I don't track which APR is which.. usually the juicier the "reward" of a card, the higher the APR. Which matters not if you fully repay.

This seems to be on par with most other store cards, for example a card from Best Buy.