Right, in cities it makes the most sense for delivery of almost anything. Even if you have a car, trying to find parking at certain times just so you can run in and grab your pizza is probably not worth it. A guy on a scooter can park almost anywhere so it quickly becomes worth the fees to have it delivered. These services have started creeping out to the suburbs where I live and it doesn't always make a lot of sense for some of them. I'd imagine delivery services are even harder to do in rural areas where you would be waiting for quite a long time to get your pizza although I could see things like grocery delivery making sense.
I agree to an extent (about the services moving to the suburbs), but if the market's there as well, I'm sure the services are fine to squeeze out every last profit.
I do use Instacart for grocery delivery (Chicago), but I really dislike grocery stores and willing to pay the premium (avg +30% in my exp) to avoid that trip. Honestly, If I was in the suburbs, with a vehicle, I might be better incentivized to personally make the trip.
Another thing I forgot to consider is people that can't leave their home for reasons other than they are tired from work or just hungover. You can get much healthier meals delivered now, much better than the pizza and chinese food that were pretty much the only option years ago. Grocery delivery is much more prevalent now too so for those that can at least cook for themselves, they don't have to rely on a family member coming by with groceries.