If you don't own a car (as a surprising number of households don't), then shopping choice is often dictated by what is close by to allow for carrying, rather than what is cheap...
Yup
Or for people who are disabled they can be limited by things like the layout of a store, or how big it is.
One of the things that many people don't realise is how hostile some store layouts are for people with mobility problems, things like putting some of the most commonly bought basics (the stuff you buy a couple of times a week) at the far end of the store may be great to force people to walk past all the offers, booze, and seasonal tat, but can make it very hard for people with mobility problems to get their own shopping if they arrive by car (and the location of the stores are often such that you do have to go by car). My local tesco is a great example of this, it's a huge store and the milk is about as far from the entrance as it's possible to put it. The local Morrisons on the other hand has the milk and bread isles basically next to each other about half way through a store that is maybe half the size.
People tend to forget that just because there are "cheaper" places to get stuff, doesn't mean that it's possible for everyone to get to them, or get around them, and if you don't have a car you can end up either spending a lot more time shopping little and often (thus missing a lot of bulk deals), or relying on deliveries which can mean spending a lot in one go and a delivery charge whilst being at the mercy of the pickers*.
Oddly Aldi, at least in my town seem to have realised this, rather than a single huge store they started out with what was probably the smallest "supermarket" in the town on the far side to me, and recently opened a second similar sized store on the opposite side of the town** where there has been a lot of new builds housing put up, and it seems to have been specifically so they could increase the total store capacity whilst still keeping the "walk in" customers at the old site (they also enlarged the old store only a couple of years earlier).
*And in the case of my local tesco that means getting bread that is often a day before it's Best before, and more than once on it's best before/after it.
**I'm more or less in the middle of them, but the new one doesn't involve risking getting stuck in traffic for half an hour at school drop off/collection time (~5 minutes away if clear, 35 if busy).