>>48719798>>48719811People commonly misunderstand this, you focus too much on the name and take it far too literally. Cosmic does not mean a location, it does not necessarily imply "comes from space".
Does Water Type mean "comes from the water"? Very frequently yes, they are highly correlated. But not always. Not all aquatic organisms are given Water Typing, and not all Water Types are aquatic. What all Water Types DO share in common is the magical trait of generating/manipulating water. That's what it is.
Cosmic Types are exactly the same. They often would have spacey origins but by no means require it. What Cosmic Type would actually mainly mean is "has cosmic powers". Which yes is EXTREMELY vague but this is fiction and it's fine to be creative with it, there are hosts of special powers you can have from vaguely-defined "star/galactic/deep power". And you can still possess these powers as a terrestrial organism, it just wouldn't be as common.