They're not uncommon but SpaceX doesnt see most, there are other higher-performance launcher platforms that can easily put these into orbit. SpaceX's next rock

They're not uncommon but SpaceX doesnt see most, there are other higher-performance launcher platforms that can easily put these into orbit. SpaceX's next rocket (Falcoln Heavy) will roughly quadruple the capability of their platform. The other SpaceX limitation is their fairing size. They designed their rockets to fit under bridges on American highways which limits the size of the payload they can deliver.