Well, it's interesting but not surprising that most people do what is logical and convenient
For people who live in apartments they have this big box called a refrigerator. When one goes to a grocery store you see all these people pushing what is called a grocery cart along which they will fill up with groceries.
If one happens to be carless (or maybe Dad needs the car for work) and live within a couple of blocks from a grocery store then they take their cart (after paying for their groceries) and push it along back to where they live. Then they unload the cart by carrying their groceries into their apartment.
OTOH, if they don't live close by to a store then what is logical changes. Can you imagine people loading up a cart full of groceries onto a choo choo train or bus? In this case they call for Uber/Lyft in order to get their groceries back to their apartment.
Or, for example, b/c Scottsdale is hub for economic activity, I have picked up a Pax at one of the grocery stores where a person may just pick up a couple of bags of stuff they want, which are easy peasy to jump in the back seat with as apposed to loading up a Schnitt-ton of bags into the back of my vehicle.
In any case for those that spend a lot of money for their groceries (and for some people $75 or more for groceries is a lot of money) then the added benefit of security with Uber/Lyft is worth a lot.
For those who have cars it may be hard to envision how those without live - but it's all very logical.