Yes, by carrying cash things might be 1% cheaper, but most people are happy to pay an extra 1% for the convenience of not carrying cash.
Many stores agree. In the U.S., there's a debate about whether cities should require private businesses to accept cash, and the only reason why it's a debate is because some stores are going cashless already. It saves them the labor of counting cash and depositing it at a bank, and it reduces the risk of mistakes, lost/misplaced money, theft/robbery, etc.