Why do only some businesses show up in Apple Maps?

Sorry if this turns out to be the wrong area to post this, it seemed themost relevant.

I'm getting our business set up in Apple Maps and Yelp. I notice that in Apple Maps each business is represented by an icon, sometimes specific to the industry but sometimes a generic grey donut. The problem is, not all businesses show up in Apple Maps all the time. I'm sitting in a coffee shop in a mini mall that has 19 stores. If I look at Apple Maps at the highest resolution, I see icons for 6 of the 19 businesses. If I search for one of the ones that's missing it will usually find it and will then display the icon and business listing as normal.

What controls whether a specific business will show up in the highest-resolution quiescent Apple Maps view, even if you've not searched for it explicitly?

The situation gets more severe as you pinch your fingers to shrink the map scale. Now, since the map resolution is lower, some of the 6 originally-displayed businesses are also hidden. What controls which businesses remain visible as you decrease the map scale?

The situation changes again if you go into the "drive mode" where Maps gives you turn-by turn directions. Now yet a different subset of business is shown as you drive by them. This is usually a very small fraction of the businesses you would see if you took Maps out of "drive mode" and look at the map at high resolution. What controls which businesses remain visible when you are in "drive mode"?

Thanks if anyone can give me a clue as to what controls this Maps behavior, or can advise me of a more fruitful place to post my questions.