It’s the delivery. I can often get something inconsequential for net cheaper, faster from Amazon. Local stock is usually next day. And I can often get stuff internationally cheaper and faster through Amazon than the real retailer.
The delivery part of the service is really good when things go right.
Very difficult to get a hold of someone when they lose a package even when they explicitly tell you “contact us”.
But if you stick to inconsequential items, it’s great. I needed a few USBC cables and charging cables the other day and got them next day at half the price. I checked the local stores and none had what I was after.
You’d have to duplicate this to take them on.