The 1% payout you describe seems to be about the max that customers end up with. Maybe some store specific cards are slightly higher, and maybe the right airline miles.
There are several cards that give 2% flat on all purchases. You can also do much better if you use specific categories across multiple cards, for example there are cards that give 5% for restaurants.
I'm dubious. I just glanced at my interchange plus billed Merchant Account Statement, and the highest I saw was 2.95% + 20 cents for a couple international business rewards cards. I suppose you could count this as 5% for an under $10 purchase, but do you have a specific example of a card that exceeds 4% on larger transactions?