I think that just like a supermarket, Produce is one thing (fresh fruits and vegetables) and Groceries are another (manufactured items like beer, coffee, ice, hooch, etc)
As long as vendors specialize, I like having a green grocer and a processed foods grocer.
Personally, I go to separate markets for produce and meat. Manufactured items are the only thing I buy from a "grocery" store. And it sells beer, wine, and hard liquor.
In the modern world, yes, produce, groceries, liquor, and even hardware are sold at most "grocery" stores, which are often little more than bigbox catch-alls that happen to have food. Why they even often have seed stands during the early spring months. In less modern times, that wasn't so, and the various items stuffed into these "convenient" monstrosities were handled by a variety of individual vendors. I expect that UR is based on a less modern concept.
I still get them confused and I've been playing for ever (lol). Thank goodness they are often close together. I even deliberately pick to visit where they are found nextdoor to each other in case I've got confused again - which still happens, when will I learn?