bts are like Michel Jackson / elvis Presley/ Bruce Lee/ Maradona... one time legends

famous artists will be after them but their impact and influence will remain legendary

It's a bit naive to assume there wouldn't be another k-pop group to reach BTS's level but then again, BTS's level isn't just a level of popularity, there are so many layers of impact and meaning that go along with it, and they're embedded in Korean and western history books, textbooks throughout schools, gov, universities, diff industries and etc. So if we talk abt the level of popularity ofc there might be another that'll become more popular but if they do it's hard to say the impact would be the same and as meaningful as BTS, but it'll still be an achievement for the artist and another achievement for the k-pop industry.

But today with the exception of BTS, k-pop still remains a genre/industry that doesn't have guaranteed sustainability in the biggest market in the world despite already being blown up there, this is one of the reasons why many believe it will die down in a few years not to mention the country's birthrate and companies debuting of young idols. So when ppl push the "will another k-pop group reach BTS level?" I can't help but say in popularity maybe. But we also don't know whether the next big thing after BTS will still be an Asian act or a k-pop group for that matter, the next big thing might be an artist/group from the Uk, US, Latin America, etc, who knows...But in the words of Legendary and global artists like the Jackson family, the Beatles Paul McCartney, Coldplay, etc, BTS is indeed a once-in-a-lifetime act and their success is hard to replicate.