Use a credit card for every single purchase that will allow it. I have the Amazon prime rewards card, and we order our dog food and many household items from there at 5% cash back.
I acquire cash back and it goes towards the balance each month. I pay the balance in full each month, thereby reaping the rewards (free money) and never pay a cent in interest. Been doing this for years.
Another reason I do this is because I do not want my routing and account numbers online with any business.
One small breach of your bank account and your life savings can be gone. I’m not trusting any big business with that, not to mention the fraud protections other users have mentioned.
If you can exercise discipline it’s a no brainier.
Costco card here, but pretty much the same argument. Aside from the points/miles/cash back rewards, most also include some minor insurance/extended warranty/travel/etc. benefits. It’s kind of shitty because transaction fees just drive up costs for merchants, but from the user’s point of view the financially beneficial option is to use a credit card for ad many purchases as possible.