I can't say the same thing OP says, because I blocked every politics community/magazine I could see when browsing all. But the truth is that most posts and comments, whether politics or not, are related to something about US.
The sad thing is that we can't do anything to bring balance onto the existing instances, so 80% of content will keep being related to US and 20% of content will keep being related to the rest of the world.
The good thing is that an instance called lemmywithout.us or kbinwithout.us could be created, similar to this magazine, but at instance level. Or we can block every community/magazine where most content, whether posts or comments, is related to US.