Your link doesn't even say that. It says that people have more
confidence in their ability to lead. The context you've made in the sentence that you inserted the link into implies that
@annoyingfuck states that he's (Trump) a super popular global figure when what he seems to have implied is that Trump has many fans globally. If anything that's a more damning thing (that they're an incompetent leader) to think of someone, but that doesn't mean it's used to be synonymous with likeability. Don't get me confused, I wouldn't be shocked if his ratings for liability are low but I don't see that posted there on the page. Furthermore, consider that most of these countries that they mention are pretty liberal. Of the 13 they include Canada, Sweden, Germany, UK, Belgium, Netherlands, France and Denmark. I'm not shocked that people in pretty liberal leaning countries aren't gung ho on someone that the media (and I assure you as someone who is from one of those countries) both foreign and domestic treats as a movie villain and pumps 24/7 content out about him. Frankly, if the media wasn't having conniption fits every two hours that alone would probably improve his ratings solely because people would be less annoyed about hearing his name.
It also leads of course to the issue of the US obviously wanting to be liked by the international community, but at the same time you can't get completely get bogged down with Sweden being asspained that you're not "progressive" enough for them to be in love with you. I'm not sure what Justin Trudeau's liability ratings are globally but I'm sure with every single country used in that study he's viewed with much more reverence (and have much less information coming at them with far less hysteria and more of a bias working to his benefit).