No, it's necessary. If meteor swarm did the same damage as a 9th-level fireball (or if fireball did the same damage as a 3rd-level burning hands), there would be no reason to learn or prepare the higher-level spell. It would be far more optimal to simply prepare the lower-level spell, uplevel it if you want that massive burst, and still be able to cast it at lower levels and use the high-level slot for something else. Higher-level spells are intrinsically far less flexible than lower-level ones, so they make up for it in power.