For what it's worth, I have paid for nearly everything I possibly could with credit cards for decades, and I haven't paid a cent in credit card finance charges in at least 15 years (since my fiancee straightened me out and helped me see that I was being dumb about debt). I have them set to auto-pay the entire balance every pay period.

I use them because consumer protections with other methods aren't as good here in the States. Paying with a credit card, if I have an issue with a vendor, after a good faith effort on my part to resolve the issue, I can just ask the credit card company to deal with it. (I don't abuse this, but I don't doubt there are people who do.)

There are better and worse credit card companies for this. American Express has great customer service but they aren't accepted in as many places.

Finland doesn't have credit score system, so there's no reason to not pay not pay the credit card bill immediately. There is certain push towards credit cards, though. As far as I remember my bank would charge a yearly fee for debit card, but credit card is free for me.

Mortgages are 70% of debt in the US. It is like saying I got perfect on a test except for the 70% I got wrong.

Not really. Mortgages are secured against the property, and attract low interest rates compared to unsecured debt like a credit card.

That's interesting. Mortgages are 100% of my debt, and the debt of most everyone I know. Which I guess was the point GP tried to make.