Please pick truly at random, not three places in the USA.
I once picked 100 random coordinates on land (by picking random coordinates and filtering out those that landed in water). OSM is by far the best. It's not even a competition. I still have to do a writeup of that some day, posting just the stats and methodology (scientific paper style) won't interest most people, and I forgot to capture screenshots, so I basically have to redo it completely.
It's almost certainly different if you select random points biased by population centres, but at least know that "not remotely usable" is a very local issue (see the sibling comments about the Netherlands) and that it depends on your use case.
I once picked 100 random coordinates on land (by picking random coordinates and filtering out those that landed in water). OSM is by far the best. It's not even a competition. I still have to do a writeup of that some day, posting just the stats and methodology (scientific paper style) won't interest most people, and I forgot to capture screenshots, so I basically have to redo it completely.
It's almost certainly different if you select random points biased by population centres, but at least know that "not remotely usable" is a very local issue (see the sibling comments about the Netherlands) and that it depends on your use case.