You're not in debt if at all times while you are using this credit, you actually have the cash to pay it off.
Then you're using credit for convenience, not as a loan because you don't have money.
People using crdit strictly for convenience, always paying their bill within the interest-free grace period, are not in debt (on account of that credit card).
Even people with significant loans are not necessarily in debt. If you borrowed $300K to buy a $400K home that is now worth $500, you still have a loan, but that is offset by equity in the property. It's not the same as borrowing to buy food, which is consumed and gone.
"In debt" is a loaded term which actually refers to a deficit situation, rather than the mere existence of loans. If we say, "OMG, X% of Americans are in debt", the reasonable interpretation is that are under financial strain due to actually running a deficit, not that some of them owe their friend ten bucks for yesterday's lunch because they forgot their wallet at the office.
Then you're using credit for convenience, not as a loan because you don't have money.
People using crdit strictly for convenience, always paying their bill within the interest-free grace period, are not in debt (on account of that credit card).
Even people with significant loans are not necessarily in debt. If you borrowed $300K to buy a $400K home that is now worth $500, you still have a loan, but that is offset by equity in the property. It's not the same as borrowing to buy food, which is consumed and gone.