Amazon gives us roughly a third of their volume. Look in the trucks in the morning everyday for about a week and take note of all the Amazon boxes. They make up to nearly a third of the volume on a substantial amount of the routes. Imagine if just half of that goes away. IE will collapse those routes.
Imagine if most, or all, of that volume goes away. Amazon isn't investing so much money in their own delivery service and network just to one day decide that it's not feasible and then give up. It will take time but not nearly as much as people seem to think. I'm hoping there are enough retirements in my center and i can move up the serenity list more before we really start losing enough volume to shake things up.