Yes, you're stating the obvious, but this service by Purism solves nothing if you think you're hiding from the mobile network operator this way, without taking other quite extreme measures on top.

And whether you've revealed your identity or not is in fact binary. This issue is not about security, but privacy.

> whether you've revealed your identity or not is in fact binary

No, it's not. It is equal to the price/time to find it out. Even though you are right that Purism does not protect from that fully, they do make it harder/more expensive.