I’m not sure that comparision makes sense. The magic of GPS is that it is one way. The satelites send signals and the ground receivers receive them. There space

I’m not sure that comparision makes sense. The magic of GPS is that it is one way. The satelites send signals and the ground receivers receive them. There space and control segment doesn’t know and doesn’t care how many users there are. Their job remained the exact same even after GPS was allowed to be used for civilian applications. In other words GPS scales very flat. Launching the constellation costs X, control activities cost Y per month. And those prices don’t change if there is only a single receiver, a thousand, or a billion. Basically allowing GPS to be used by civilians didn’t cost them any extra on top of what they were already paying to keep it operational for the military. Plus there is no natural limit on how many gps receivers there can be. This is not the same for Starlink. There user stations have a two way connection with the satelites. The system have very real limits on how many users it can serve. And every new user cost something to the provider. Because of this the government would need to manage who can have access and how much they can use the constellation. That would be a nightmare to manage for a government and everyone would be unhappy with them. In short: not a good idea.