Wait... Focus doesn't use Google Analytics because they don't meet your very high standards for privacy. But it does use Adjust, which means Adjust does meet your very high standards, even though it uses Google Analytics?
This is a misunderstanding. Adjust does not use google analytics. You are connecting unrelated things. The existence of a library, which actually is not a google analytics library, does not mean at all this app talks to google servers.
AFAIK Focus and Adjust make no connections to google. Check the source?
But Adjust only comes into play when the app is installed by clicking on a Google ad campaign. So at that point, Google already knows you've clicked on the ad and installed the app (because that's how they bill Mozilla).
I don’t think Adjust is for Google ad campaigns actually. It is used for links we put in our emails or in Firefox desktop. Or for ads that we buy on Facebook. I don’t think there is any connection to google.