I have never cared what CC interest rates are since I don’t carry balances.
The best way to use CC is to get 2 or 3 new ones a year for the sign-up bonuses worth about $500-800 each.
The second best way is to get the rewards. These days the best rewards are #1 Fidelity which is a flat 2% cash back on everything, and #2 is Chase Freedom/Sapphire, which is more complicated but is worth at minimum 1% in cash back and at max 2-3% for travel rewards.
Chase can be converted to Southwest points worth about 2.1 cents, and together with the signup bonuses I have used about $2000 in free southwest flights over the years.
Unless you fly Delta a lot, Amex has been lagging Chase and Citi on rewards the past few years.
