It seems to me that a legitimate test of a religion is whether there would be anything left of that religion if all present traces of the religion were abolished. The test would then be if that religion, whatever it would be called, re-emerged anew at some place and time among human communities. Buddhism, as a path of truth that is discovered by direct experience and insight, would emerge again and flourish. By contrast, it is inconceivable that any religions "of the book" could exist once their current texts and tradition ceased. Christianity, Judaism, Hinduism and Islam are tied to their history and elaborate theologies, and once that is forgotten, they would cease to exist. Unless you seriously believe that some divine creator exists to restore that religion, they would cease as soon as humans ceased to believe in them.