I never thought that 2 cities in Indonesia are listed as top 10 overrated destinations in the world according to Radical Storage's study - https://www.timeout.com/news/these-destinations-have-been-named-the-most-overrated-in-the-world-121622 On the otherhand, I think Argentina is one of the most underrated countries with a lot of tourist spots or things to do. You can visit Salta and Bariloche which offer natural and scenic view. If you love to experience phenomenal nightlife, Buenas Aires is the best place to go. It is also rich in cultural and national heritage where you can enjoy and learn about its history https://gowithguide.com/argentina/buenos-aires.
Though there are other underrated destinations that are worth visiting such as Slovenia and Taiwan.