It would connect you with what actually matters to the customer. You may be building features for the developers that paper over or hide issues for the end user. I've see this where frameworks chose metrics that paged engineers less but caused micro outages. Not saying this is you but the end user's experience is the core product. Sometimes you have to make the devs life a bit worse to make the customers better. Hopefully you get to come back and also make the devs experience better over time.

Humility?

The possibility there could be something to learn by personally understanding/experiencing your employer's core business?

Developing a shared sense of empathy and responsibility towards making the jobs of the drivers as efficient as possible?

Empathy is a powerful thing. We make many little decisions during the work week around if it's ok to take something down, if an engineer's request needs to be handled immediately, etc. I think the goal of the company is to align everyone around empathy for the drivers (I presume you're all already customers), so that you make those decisions in ways which enable engineers to deliver software well.

It's just feel-good horseshit. DoorDash wanted some PR, and CNN is there to give it to them. Now we're discussing them by name on HN. It's all very clever.

I think it's important to use your own product (so get food delivered), but I don't really see any value in doing someone else's job as a pretend fantasy for a day. If you have any empathy, you'll know that the work isn't so bad, but the lack of health insurance, childcare, long-term career growth, etc. are the problems with the gig economy. The job itself is fine. The most positive outcome is probably having the realization that the gig economy is quite abusive and that you want nothing to do with it, so stop working for the company entirely.

You should learn that this is what would have happened to you if you had not worked hard during your education years. Now you can pass that lesson on to your children. :P