Mobility would be nice to have available at any moment, depending on where I want to go. However, I live in the city and I can get around most places on foot or on my bike. I might use a car service in particular if I'm heading out to an event or a meeting across town.
Food on-demand is helpful, but not all the time, as sometimes I like to eat in restaurants or go for a walk to my favorite sandwich shop. I also like to cook. Getting the ingredients delivered to my home would be useful, but I don't mind making quick trips to a grocery store for certain items. If I did not like being around people, then a grocery shopping service would be very helpful.
Office services would be a good candidate for an on-demand business. If I need more coffee, paper, pens, or new equipment, then I imagine that I could call someone that could deliver the product or service within a particular time window. That seems reasonable, except if there were a delay in getting what I need.
I often wonder what people expect to be on-demand. Is it the product itself or the delivery process? Is there a difference?