"I think it's pretty obvious that Instacart's exit strategy is to make some great technology that either Amazon or Google will buy-out."

I think they will make a play to open up their shop and delivery service via API to eventually allow stores to use them as a full end-to-end delivery service and sales channel.

The other play is to do what DoorDash is doing with focusing on the core logistics/driver infrastructure and route/scheduling optimization software. Doordash is generic enough to go beyond restaurant delivery and become an open alternative to last-mile courier services in the market today. It's basically Uber cargo but I think they could do so much more by making it an open service that any business could use to handle on-demand delivery to their end users. If Trader Joes wants to provide delivery, they just need to be able to ping DoorDash with an address and have a box ready when a driver arrives. This offloads the liability and capital costs associated with having your own drivers and delivery trucks, etc.