There’s a popular saying in videography: The best camera is the one you have with you. That’s true to a certain extent, but if your goal is to get a specific type of video, there are certain cameras, lenses, flashes, and other gear that are best suited to the task. These often cost thousands of dollars and can be the difference between images that are adequate and awesome.
Consider the 70-200 f/2.8 lens. These are expensive, heavy, and impractical for casual individuals who enjoy snapshots with their phones. And while you could spend the equivalent of a few month’s rent or car payments on one of these lenses, you might be better off forking over a fraction of that amount to a professional instead.