My partner and I pay our cards off in full each month avoiding any interest payments to the credit card companies. Once one of us unlocks the travel points on a card, the other opens a different one. Other than the nominal annual fees, there hasn't been any downside since we don't carry interest accruing debt.
We have paid for two trips to Mexico completely with points, and we are going a Vegas/Hawaii/Vancouver trip next summer 100% covered with points. This is a huge benefit to us since we are working class, I am a civil servant and partner is self employed. There are also other perks for us like free streaming services for 12 mo, free Instacart membership, free luggage etc. I think where people run into a problem is accruing large balances and paying more back to the card companies than what they earned in points. If you are smart with them, you can actually take advantage of the financial institutions. Of course, the GOP will probably now allow them to back out of their promises to consumers. I'll definitely be keeping an eye on how they handle regulations on these offers.