Minimum distance between markers

Each red circle in this map is a point but due to the density of them, there isn't enough space to show the text labels for all of them. So I want to filter them down to just show those which can show a text label.

How can I do this? marker-spacing seemed to be promising but makes no difference. I see no "marker-min-distance" as there is with "text-min-distance".

Basically there's no point in showing a marker at all if it can't be identified with text. This is for a non-interactive offline map.

There is marker-spacing.

If you want to draw only labelled markers, use shields instead (answered here).