system
Given the following post, respond as if you're commenting on Reddit:
human
[marvel]Why is galactus a cosmic entity?

Sure, he eats a couple of planet or solar system once in a while, but there are hundreds of billions of galaxies out there. He should be seen no more of a threat than a supernova or a black hole. What gives galactus the right to have the same title as infinity or eternity or master order?
gpt
Firstly, do not assume that the size of the Marvel universe is the same as our own.  We don't know for sure that it's not, but the DC universe is explicitly finite so it's not like ours.  
Secondly, it's not about destroying planets, it's about what will happen at the death of the universe.  Galactus is the last survivor of the previous iteration of the universe.  When the next death of the universe happens, Galactus will "release" all of the energy he has collected, and this will provide the energy for the next big bang, and another being will take Galactuses place (Mr. Immortal is the top contendor).  This is what makes Galcatus a cosmic entity, his importance to the universe, not his destruction of planets.