Publishing on MuseScore

Could someone kindly explain what happens to a piece when it's published on MuseScore? What's the point of publishing here? Who sees/hears it? Do actual independent music publishers ever look on the MuseScoreI site for new pieces to publish? Can any $ be made from publishing here? Is a piece published on MuseScore automatically copyrighted to the composer? Does it somehow become MuseScore's property? Can it be "lifted" by some nefarious lookiloo? Finally, I am thinking of publishing a recently complete piano concerto on MuseScore, in hopes of finding a professional pianist and/or conductor who would want to perform it with a live symphony. Is there a chance such a thing could happen here? Sorry, lots of questions- any answers would be greatly appreciated. Cheers and best wishes, Tom Smith