As a consumer with children, it's a major hassle to go to the grocery store with my kids in tow. It's also unacceptable to wait 2 days to get what I order.
The ideal solution would be for me to go to Amazon Fresh, pick my location so I can be assured that everything listed is in stock, and then do my shopping.
On their end, the workers would pick the products from the shelves and toss it into bins with a barcode on them, just like they do at the Amazon Warehouses now. There would be 3 categories of bins: Frozen, refrigerated, and room temp.
When my order is ready, I would get an alert on my phone.
Then I would drive to an Amazon Fresh site and park in a numbered spot and either press a button on an adjacent speaker box or something or enter the parking spot number on my phone.
I would get a notice that an attendant is on their way. A few minutes later, a cart would come out with the bagged groceries and the attendant would load them into my car and I would leave.
This really seems like the best choice for Amazon. It lets them have regional centers for product warehousing so they don't have to ship cross-country, it lets consumers get products instantly without last-mile logistics problems, and it would let them gradually transition to their own in-house delivery for their regular products and not focus on the products that need instant delivery. Having their own delivery unit, UPS, and local delivery companies would encourage competition and keep the prices low for them.