Convenience, safety and lower costs. When you're cooking and you forgot some ingredients, push a few buttons and 10 minutes later your order arrives, sans humans and hassle. Like pizza delivery, but for everything and with fewer costs. Lower costs mean smaller transactions become economical. No flying bladed helicopters mean reduced risks and requirements for landing spots.

We have grocery delivery in my area, but it's such a hassle because I have to be home within their time window and I have to book it a couple days in advance. Why can't I just hit a "now" button and it arrives via drone, at 2am if I so desire, when most delivery people are sleeping? Or in a rainstorm, because the drone doesn't care?

Maybe the people have reduced mobility. Maybe they have small kids or elderly people they can't bring with them nor leave alone. Maybe they have an extremely busy schedule. Maybe the streets where they live are dangerous for cyclists. Maybe the packages are too big to safely carry on a normal bike. Maybe they just don't have a bike or even know how to ride one. Maybe they just don't feel like it.