The first huge advantage of the Hubble law is the ability to see objects without the obscuration of the atmosphere, the atmosphere distorts and obscures a great deal of light from distant and dim objects. By placing the telescope outside the atmosphere this problem is eliminated, also the Hubble being space based can observe phenomena that might be completely missed by land based telescopes because they occur during daylight hours at the land based location. There is no daytime obscuration of the stars from space.
Electromagnetic waves do not require a medium in order to transport their energy. Mechanical waves are waves that require a medium in order to transport their energy from one location to another. ... Sound is a mechanical wave and cannot travel through a vacuum.
