What is an advantage of foam-dielectric versus solid-dielectric coaxial cable?

In a coaxial cable, the dielectric is the insulating material separating the center conductor from the outer shield. Solid dielectrics use solid plastic (like polyethylene), whereas foam dielectrics inject tiny air bubbles into the material. Because air is a highly efficient RF insulator with less signal attenuation than solid plastic, foam-dielectric cables have significantly less signal loss per foot. While lower loss is a great advantage, foam dielectric has notable drawbacks. It actually has a lower voltage breakdown rating than solid dielectric. Furthermore, if the outer jacket is cracked, the foam will soak up moisture much faster than solid plastic. Finally, either type of dielectric can be perfectly matched to a 50-ohm impedance.