I agree that delivery services provide significant value to the consumer for the reasons you describe. I suspect that in the situation where a specific class of restaurant (pizza places) already have their own delivery network in place (fixed costs already paid, domain-specific efficiencies already captured), a bare-bones online order system could easily beat out a full-service middleman like UberEats or Grubhub.
Here is a neutral (from the perspective of potential competition) source, that quotes industry insiders: https://nypost.com/2016/02/06/tech-giants-start-getting-serious-about-food-delivery/
I agree that delivery services provide significant value to the consumer for the reasons you describe. I suspect that in the situation where a specific class of restaurant (pizza places) already have their own delivery network in place (fixed costs already paid, domain-specific efficiencies already captured), a bare-bones online order system could easily beat out a full-service middleman like UberEats or Grubhub.