Something about the lack of visibility as it relates to establishing norms - can't see a credit card tip - common wisdom of the dollar in the tip jar
I'm broadly not a huge fan (prefer to call in or go myself). But I also know that online ordering is contributing from a wide phenomenon of overworking and unreasonable expectations in kitchens (fueled both by customers and management). Particularly because most apps don't allow restaurants to cap orders per hour or otherwise indicate to customers how busy things are in the same, human way that calling in and having someone on the phone tell you, in their voice, that it'll be an hour because their busy does. The instantaneous experience of ordering masks the real work that goes on behind the scenes and allows people to ignore that labor even more than they usually do (which is why they get way madder if they have to wait 5 minutes in the restaurant when the order online).
I worked for a while doing bike deliveries for Postmates one college summer. Besides a woman who told me, sweaty from biking to the shop in the New York summer, that the delivery, an elaborate pastry in a mason jar, couldn't go in my bag and had to be carried two miles by hand, the most memorable interaction I had was an absence. After waiting in line at Shake Shack for twenty minutes and biking ten more, I was greeted at the door of this upper west side apartment by a woman holding a broom. I heard FPS sounds in the distance. Kyle or whatever gave me no tip. I made $4 that hour.
The one wrinkle is when the delivery is actually made or the order actually picked up. But that's easily smoothed over by avoiding eye contact and glancing at your phone.
Things like Uber eats relocate the perceived labor, from the perspective of the consumer, onto the consumer and the software. Paired with the instant gratification and the convenience is an odd sense that somehow you did all the work. I filled out the form. I placed the order. Despite our lives online our perception of labor still lives between our hands and in our sense of time spent. This is what differentiates the Ubers and Postmates of the world from the catalogs and called in meals of times past and even separates it from Amazon (try as they might to push that delivery time down to zero) is a sense that you (with the infinite “free” labor of a phone) made the magic happen.
It is psychological gravity, not technical inertia, however, that is the greater force against the open web. Human beings are social animals and centralized social media like Twitter and Facebook provide a powerful sense of ambient humanity—the feeling that “others are here”—that is often missing when one writes on one’s own site. Facebook has a whole team of Ph.D.s in social psychology finding ways to increase that feeling of ambient humanity and thus increase your usage of their service.
— Dan Cohen, https://dancohen.org/2018/03/21/back-to-the-blog/