Final answer:
The story of BTS and ARMY could continue for many years depending on the group's musical activities and the fans' continued engagement, but accurately predicting its duration is not possible.
Step-by-step explanation:
The longevity of BTS and their relationship with ARMY (the name for BTS's fan community) is not something that can be accurately predicted. K-pop groups often have a diverse and vibrant relationship with their fans that goes beyond the music they release. As of 2023, BTS has been active for nearly a decade, and they have amassed a large, dedicated fan base around the world. The connection between BTS and ARMY is deeply emotional and culturally significant. While the future is uncertain, the story of BTS and ARMY could potentially go on for many years, as long as the members continue to perform and the fans continue to engage with their music and brand.