The lifespan of a music group's popularity can vary widely and is influenced by multiple factors, including their music releases, promotional activities, fan engagement, individual members' career choices, and changes in the music industry landscape. Some artists experience a surge in popularity and then gradually decline, while others maintain their relevance and fandom for extended periods.
It is worth noting that BTS has managed to build a strong and dedicated fanbase due to their music, performances, social media engagement, and philanthropic efforts. As long as they continue to produce high-quality music and connect with their fans, they are likely to maintain a significant presence in the music industry. However, predicting the exact duration of their popularity is challenging, as it depends on numerous unpredictable variables.
To get the most current information on BTS's popularity and the state of the "BTS mania," I recommend checking recent news, music charts, and social media trends.