One thing I think other's haven't mentioned yet: US internal politics specifically make headlines worldwide, certainly in the western world. That's not true of German, Swedish, Israeli, or any other country's internal politics. This is probably because USA is arguably the only real remaining superpower, or something close to it. Regardless of the reason, US politics are uniquely loud and everpresent, which I guess is why they were singled out.

Edit: I once saw a subreddit's mod post explaining this better than I did, but I can't find it at the moment.

Internet users are 90% Americans on Lemmy or on the technical forums. It's to prevent being flooded with US stuff.

But I am curious to hear why it is specific to US politics.

You've already gotten the biggest reason but another one to consider is that there are other large countries trying to force the world to become multi-polar. Those countries spend a LOT of time, effort, and money making sure that every possible negative aspect of American politics and culture is brought to light as much as possible.

The Russian troll farms and China's 50 cent army don't sleep. They're always active and always looking to push negative coverage of the United States. They simply won't allow a focus shift because they are paid to keep that spotlight shining bright at all times.