You might be interested in another piece I wrote for GEN about the ways in which the group BTS has made use of social commentary both inside and outside of their music, which is potentially part of what inspires their fans:

https://gen.medium.com/bts-are-on-the-front-line-of-south-koreas-generational-warfare-3d656bcfc160?source=---------7------------------

Additionally, when I spoke to One in an ARMY, the fan-led charity group within BTS' fandom, they told me it was greatly inspired by BTS' own charity efforts.

https://glitch.com/glimmer/post/bts-army-charity-fundraising-fandoms