I work on something similar and wondered about that as well. I wanted giant stars and supermassive black holes to be perceived as incredibly huge (which they are). My thought was that any star would "look" and behave the same if you simply stood further away.
Meaning: A star with the diameter of 10 at a distance of 50 will look the same as a star with a ...
I was having this same problem when making a build in windows for unity IOS and then porting over to my Mac to build with Xcode. Unity provides a Podfile in it's IOS build to get the Google Ad SDK.
Solution that worked for me:
Open terminal on your Mac
In terminal: sudo gem install cococapods
After it finishes navagate, in terminal, to your project ...