A question you need to ask yourself is "How much is it worth to me that someone brings me this food instead of me getting off of my ass and getting it myself?"
if you actually believe this, then i'm curious how much you tip your mail man or postal employees annually. because by your logic, i should be tipping my mailman roughly thousands per year when you factor in the service that is being provided to me for MERE PENNIES - that is, a collection of postal employees (mailmen, sorters, drivers, etc.) take my letters and deliver them to somebody else's door across the country, or even across the world, in less than three business days. That's a pretty incredible service, and requires far more collective effort, teamwork and dedication than it does for some idiot high school kids to box up your pizza and drive it three blocks.
i mailed a family member a birthday card a few weeks ago. for me to do it myself, i would have had to buy a plane ticket, travel across the country, get a rental car, drive to the house, drop off the envelope, stay overnight at a hotel, drive back to the airport, get on plane, fly again, pay for airport parking, etc.
so, in truth, the service provided was worth A LOT to me.
and yet, it cost me just 46 cents.