What would be an Amazon-killer for me as a consumer -- and just about the only thing that I can imagine that would be -- is something like Amazon that connected me to the inventory of local merchants where I could buy things for same-day or next-day delivery via something like Doordash. There is a ton of inventory within a 30-60 minute drive of my house (in the Bay Area) but no centralized service to connect me to it, so if I want some glassware and some shower cleaner (my actual current use-case) I have to visit two different merchants, place two different orders, set up two accounts, take twice the risk with my credit card number, etc. A centralized order dispatcher that was connected to local inventory and delivery which would let me order everything I needed all in one place and know that fulfillment would come from local merchants that I can trust to vet their suppliers would kick some serious tushy.