This is absolutely not why millions of people use credit cards. To repeat: Immediately handing cash to a merchant carries risk for the purchaser. What if the product is defective, or the order never filled, etc?
If it's in-person you bought something, technically you can only return up to 30 days for non durable goods, and 90 days for durable goods, if there's some problems with the product, or a reason etc.
The risk is buying from shady merchants and platforms that don't care about the legal system, or can delay the resolution of the dispute.
For instance buying from China on AliExpress, I will obviously not use Pix (through AliPay), but my credit card.