If there is anything about BTS I have realised it is that they are the BEST when it comes to picking a particular song as their main single. And they have been the best at it for 9 years now. I mean they could have easily chosen songs like 'DOPE', 'Mic Drop', 'Save Me' because they fit the "BTS identity" but they didn't and the songs they chose during these comebacks tuened out to be turning points in their career. I even made a thread why their main singles are the biggest reason behind their success because I have realised that they always think it through when they choose a particular song to be a main single.
Being an older ARMY, I thought you would know that BTS release songs for the present situation they are in, their feelings during the time. 'IDOL' was released when they were being called "sold out" & "westernised" is a proof big enough.