I think you are underestimating the number of double-spend attacks that a business like Amazon would face if they never waited for confirmation A double-spend

I think you are underestimating the number of double-spend attacks that a business like Amazon would face if they never waited for confirmation A double-spend is costly, a chargeback has no cost. One would think the number of double-spend frauds would be lower than chargeback frauds simply because these are more difficult.