The goal is orbit, and orbit means going very fast sideways at high altitude, where this launcher can't point (because it's at ground level). So, you can't go

The goal is orbit, and orbit means going very fast sideways at high altitude, where this launcher can't point (because it's at ground level). So, you can't go "all the way" without putting in sideways thrust to turn your trajectory into proper orbit. Without a rocket to provide that sideways thrust, this launcher will throw things up in a ballistic trajectory, and they'll come back down to Earth with a big crash (given enough sideways velocity, they'll "miss" the Earth and be orbiting).