The points are for bragging rights. The purpose is to entice users who who care about where they stand on the scoreboard into performing certain beneficial functions to make Waze a better app. For example, A person that makes map edits in Cartouche would get editing points that are worth a certain amount. Users that drive down less traveled roads and "munch points" get points for exploring that road. Users that report road and map problems get points. Even chatting with other users or just driving down a road gets you points. The whole point is to make Waze a social experience where the more you use it, the more points you earn and thus raise your rank on the scoreboard.

It's just for the fun. It isn't anything important.
You can't unlock thinks.