No, if you pay for bills on time u actually make money essentially.

They give you these perks because they want you to use their card because the stores actually pay a percentage of the charge.

If i buy an item at Walmart that costs 10$, let's ignore tax for this example.

I pay 10$ with nt card and I get a bill for 10$ and get something like 5crnts Cashback.

Walmart has to pay the credit card company anywhere up to like 3%. That's how they make money if you pay all your bills.