I thought they were built on "time is money". If you make the equivalent of $70 an hour, do you care about spending $15 for someone to bring you lunch and save you 15-30 minutes of your workday?
Edit: Spelling. “right” to “sick”.
Well, if you value an hour of your sleep or entertainment less than $15 dollars (if, for instance, you like to cook), then sure, spend it on cooking instead. Many of people would rather not, and their revealed preferences show it pretty clearly.
You might say "going home from the office 30 minutes earlier is absolutely worth $15" to me, but that has little to do with what your effective hourly wage is.
If you can't pay the wage you're required to then the whole house of cards starts coming down because now you can't create a large enough network to meet demand, which shrinks demand, which increases costs, which makes it accessible to fewer and fewer high paid consumers.
Like a lot of capitalism "it's better than starving to death in the streets" is the appeal of the job and nothing more. Anything else is a paid message brought to you by UberDoorHub.