There's a huge network effect that's effectively led to a 3% tax on the economy. Since every other store accepts credit cards, you need to too. It's not a case where a credit card allows someone that was going to buy a $500 TV to now spend $1,500. It's that you won't sell anything if you're a cash only business. And with Covid fewer people want to handle cash.
Debit cards exist and partially solve the inconvenience of holding cash. But, they're really inconvenient in other ways. As a consumer I'll prefer credit cards most of the time just for the security benefits. If there's a breach at a merchant and my number is stolen I don't have to worry about my checking account being screwed up for however long it takes to sort things out.
It'd be nice if we had another option for cashless payments. Particularly, one that doesn't impose such a large financial burden on everyone. Yeah, rewards are nice but they're disproportionately allocated as well. I think it's fairly evident going forward cash will be handled less and less. Credit card companies are the incumbents and path to least resistance to accepting cashless payments, but they don't need to be the only option.
With real competition I suspect we'll see those swipe fees suddenly decrease. Unfortunately, some of the bigger attempts at non-credit card payments (e.g., PayPal) charge commensurate fees. So, maybe I'm off and 3% is the minimum needed by the middlemen to stay afloat.