Just as a heads up, ypu dont need to carry a balance and be charged interest - you can pay off your cards each month never paying interest and still have an improved score, simply pay the statement balance before the due date
I’ve seen people have their cards cancelled for doing this. Rare, but not unheard of.

If you’re doing that you have zero need to bow to any single credit card company.

I don’t even read 90% of the credit card offers I get, I have plenty of cards, and they are all at zero. Go ahead, cancel me. I’ll have a new one in 15 minutes.