Ha ha... we'll see I guess. I came here to post about the poor people that ordered Xbox One X because Microsoft can't come up with a decent naming convention and the old console name is to close to the new Xbox Series X for some people to keep straight. See you beat me to that news with your post from last night. UGH.
Beyond that, I will note that a physical cart is much different than your ecommerce cart. I get your comparison and frustration, but it is a completely unrealistic expectation/comparison. I work with software for point of sale and for ecommerce. Same concept, big differences. If you see a physical item on a shelf, lets call it a widget, yes you can put the widget in a cart and take it to the register and you get to purchase it. Heck, the system might even think they've already sold every widget or think they have negative widgets, when you take the physical item to the register and you will be able to purchase it, because you have it in hand. If it happened that you and 1 million others were trying to buy that last widget on the shelf, you'd all have to duke it out and only 1 of you could ever get that item into your cart and up to the register. Digital carts are completely different. You aren't putting any physical inventory into a cart and taking it to a register, you and millions of others could all be looking at the 1 item left and be trying to add it to your carts at the same time - generally these systems are going to work off some estimated inventory counts to try to prevent scenarios where too many people have orders that have to be cancelled or end up back ordered.