there are a lot of reasons people have but there is not anyone who does not pay their credit card bill because there is not enough money in circulation to allow them to do so. They don't pay because they don't have the money, not because it does not exist.
The system is built on people borrowing more than they can easily repay but that does not mean you can't use it to your advantage. I use credit cards for everything all the time, I have had several zero percent cards over the years. I pay on time and as I result I never pay a dime in interest, I get miles and points and cash rewards and discounts and free tickets and all sorts of crap, the credit card companies call people like me "deadbeats". They are giving away free money, you can choose to take it or not, you can also choose to put yourself into debts you can't easily repay and be the one of the people paying the credit card companies so there can be the free money for me.
I also used interest free cards for a few years a long time ago. Then I learned that the 'credit' is not a valid loan in law and that actually the entire industry is an elaborate form of fraud.
and yet here I am sitting on a couch I purchased interest free. ;)
but if you were paying attention you would see that I didn't pay the bank one cent and that I don't owe them anything for the free money they gave me.