Ok, but you have to worry about detecting fraud. Without a PIN/MFA attackers have it much easier time doing fraudulent transactions from the start => more time

Ok, but you have to worry about detecting fraud. Without a PIN/MFA attackers have it much easier time doing fraudulent transactions from the start => more time spent by everybody checking transactions. And even if you have peace of mind, I wonder who pays for the cost of the fraud. I would imagine the bank will just pass it over to the consumer in some fees. So a system that reduce fraud (even if can't eliminate it completely) is still better in my opinion.