Not sure how legitimate my source is but it looks like they raked in ~$75bn in 2020 from interest income alone. That makes me wonder if those of us that do use a CC as a debit card are a minority.
Very much a minority. The average credit card balance is over $5000 according to https://www.creditcards.com/statistics/credit-card-debt-stat... And the interest rates are ridiculously high so they can afford even a large number of people paying off their bills each month.