Yea, if you think his actions didn't effect the globe you aren't paying attention. For example, if he took covid more seriously, other nations would have been more likely to as well. Pulling out of the Paris climate accords has a worldwide effect on climate policy. His close ties with Putin set the stage for the war in Ukraine. That alone has effected everyone from energy and food costs, extra money and military supplies to support Ukraine, to setting precedent in the modern era on invading sovereign nations. I also think him getting elected in the first place gave a voice to and swung the political pendulum hard to the right globally. Had he not won, I don't think you'd see a new era of Nazis or their 'acceptance', you probably wouldn't have had brexit, and fewer far right groups winning elections.

I care, because the influence of American politics in other nations politics is undeniable. The shockwaves, caused by Trump's antics, are perceived around the world. Some countries even had/have Trump likened figures in power. I feel like Maga straight up emboldened right wing parties around the world, to get out of the closet and be more verbatim about their cause.

My main worry is, that it's something that's being embraced by a steadily increasing, already big, number of the population, in many countries around the world.

We have a scary political trend here in Germany right now.