* No significant rewards because the fee is capped at 0.3%.
* Chip and pin because that decreases fraud more than chip and signature.
For many businesses, a 2-3% fee is so much of their total profit margin. For example, Google tells me a full service restaurant averages a 3-5% profit margin.
Dropping a transaction fee 2%->0.3% would mean a 3% margin turns into a 4.7% margin. All else equal, 56% increase in profit!
There are other considerations, like would people spend as much if they didn't get rewards. I don't know the answer, but another question is "what's best for society?". In my opinion, credit card companies commonly act as a low-value-add intermediary and a wealth transfer from the poor to the rich. [1] People are paying more because that fee is baked into every single transaction, whether credit, debit, cash, or check.
They do provide a great indisputable paper trail for many transactions, and going 100% cash probably isn't best for society because there would inevitably be more "untaxed revenue", but 2-3% is outrageously large fee to pay.
[1] https://www.bostonfed.org/publications/public-policy-discuss...