I recently read an article written by folks at the Federal Reserve titled "Who Pays For Your Rewards? Redistribution in the Credit Card Market".
Their analysis showed that the general idea that the poor subsidize the rich (Reverse Robin Hood) is not entirely true. They found that financial sophistication is a better indicator than just using income. This is defined as understanding and knowledge of how credit cards, interest, budgeting, and payments work. FICO score is a better measure for this than just income.
The one point in the article that was mind blowing was that the authors surmised that high-FICO consumers benefitted from rewards programs at the expense of low-FICO consumers to the tune of $15.1 Billion annually.
The credit card game can be very lucrative but you need to pay your bills on time without paying any interest and you need to keep your spending in check. The largest banks in the US gave out $35 Billion in rewards in 2019, but they do this to entice you to spend more and not pay off your balances monthly.