A big reason many people become wealthier is they take advantage of every opportunity to boost their earnings. And scoring cash back on essential purchases fits into that system.
Anyone who uses credit cards can routinely rack up reward points or cash back on their purchases, no matter their income status. The difference is that people with a lot of money tend to spend more money — and so they score even more cash in the process. Also, wealthy people may be more likely to qualify for credit cards that offer uniquely generous reward programs, maximizing their cash back, air miles, or hotel points.