But Alec, they never clutter up the screen. They simply can't. GPS manufacturers are well aware of this as a potential issue, so take steps to ensure that it cannot happen. They do this by hiding all icons until you zoom in for a close-up view (commonly about 50 meters). In practical terms, this means that you will hardly ever see more than one or two POI icons on the screen at any time. No clutter there!
If you want icons, but think they are too obtrusive, you could use smaller, more discrete ones.
Still too much "clutter"? Use a very small coloured dot as an icon for each POI.
If you really, honestly, truly do NOT want POI icons on your GPS under any circumstances, simply don't load them - just load the POI coordinates. You can still use your GPS to navigate to any chosen POI and you can still pull up a list of, say, all the nearest Dumpstations. You won't be able to see their positions on the map, though..........