Synchrony is going to cancel your account. Even if they can’t then they’ll just cancel your other accounts with them.

I got it for Uber 3% cash back. Then the pandemic happened and I stopped taking rides. Then I got the Chase Reserve which has 3% cashback on all travel (including Uber) and 10% for Lyft. So now I just use it for app purchases. For buying Apple products themselves I buy Apple gift cards from Target at a 5% discount. So that’s 5% cash back which beats what you are doing.

Because it is all written in a language that only has signed numbers. That’s virtually all modern languages.