Why would I directly use it through browser and not third parties? What is their differentiating factor? I am not being facetious, but just being curious. I only know 4 square and maybe Apple uses their data.
Because in a lot of places, OSM has more accurate points-of-interest coverage.
I maintain the map for a fair chunk of Soho in London. On Google Maps, I've seen places I know about filled with points of interest that aren't actually there, geo-targetted SEO spam and so on.
For various bits of London, if the map says it's there, I either put it there or checked it.
I just checked an area of London that I maintain for OSM but on Google Maps: it's a load of shit. Shops and businesses that closed years ago still on the map. Large corporations inside police stations. The Victoria Embankment Gardens marked as being in the River Thames.
Depends on what your use case is. If you just want maps on a page, third party is the fastest, easiest way to go, no doubt.
The key point with OSM though is that if you actually want to build something with a geo aspect that uses the underlying data you can. With Google you can't. That of course doesn't mean it's easy to do, but the possibility is there.
