This sort of thinking misses the point that even with credit cards you don’t spend what you don’t have. You (ideally) treat it like a debit card. If I spend $100, then I’ve $100 less in my checking. If you do that, then “flush” never enters the equation.

But when that card statement balance comes due every month, it should make no difference because the cash was already deducted from my books when I made the charge.

I get some small amount of Amazon vouchers every month for doing this (£10/m or something like that), but really I do this for the fraud and chargeback protection.

I feel like this works well for us, but you have to be able to budget - if you're not capable of budgeting or find credit too alluring, then you're better off using a debit card.

A friend did all her banking in a single checking account. Her card was duplicated and completely wiped out. She filed with the bank for fraud charges. It took almost a week before most charges were wiped out. All the while she had literally no money to eat, buy gas, etc. If that was a credit card, it wouldn't matter. She would still have all her money. She could easily just use a different line of credit, use cash, or use her debit card.

So paying a debit card gets you far less benefits and depending on viewpoint carries higher risks. But the benefit is you (sometimes) can't spend cash you do not have.