I don't care if this offends, and it may seem obvious to some, but I just felt like saying this, especially after seeing Army demanding apologies from South Korea and declaring South Korea would be nugu as a country without BTS.
Do I think BTS opened a lot of doors for K-Pop in the West? Sure. But it's not like the industry was on life support before BTS got big. I was a K-Pop fan for half a decade before BTS took off.
K-Pop groups were already starting to become more active in the West before then too. Hell, that's how I actually saw BTS perform in person. They were in the KCON NY 2016 line-up (of course I was there to see Mamamoo, not BTS).
BTS are living legends, but even if they didn't escape nugudom and disbanded, K-Pop as we know it wouldn't be dramatically different. Butterfly Effect probably kicks in and some other group fills the void