There will be a single payer system that will deliver to everyone. They'll call it something clever, like "United States Postal Service." They'll organize delivery areas and rationalize it so that only one delivery person needs visit every street every day. No congestion. Predictable delivery.
Seriously, this seems to have become a "problem" with the Amazon doing it's own deliveries. I see more generic white vans with Amazon logos than I do Fedex or UPS trucks.
What I don't get is why it wouldn't make more sense for Amazon to partner with USPS to handle last-mile delivery. They could pre-sort by zip and deliver in bulk to individual post offices once a day and let USPS deliver it.
I suppose Amazon is Uber-izing package delivery, and making it a race to the bottom job.