Switching away from tipping isn’t the worst solution, because a lot of people need to get paid. There are more parts to the puzzle than the shopper that is in the face of the consumer. But… there is a right and a wrong way to deliver the promise of “No Tip Accepted” — Instacart is going to need to be vocal that “YES, we’re going to charge more per item than it would cost you to shop in the store — BUT — we’re taking good care of everyone involved in letting you go about your day and have your groceries.”
What these people do is far more difficult than delivering a pizza. You wouldn’t want your pimple-y delivery boy choosing the best produce for your family. What you get is a competent shopper.
Here is how my favorite podcast, Freakonomics, covers the successful method of initiating a successful no-tipping scenario in their episode, “The No-Tipping Point”: http://freakonomics.com/podcast/danny-meyer/