It's a given that any group can and will have millions of streams as their fans will always listen to their songs. But to me, the real test of a group's popularity and reach is if I hear their songs being blasted by my neighbors, by the internet cafes, malls, etc. Especially the boomers? They may not always know the group's name but they respond to BTS and BP songs. Their grandchildren dance to those.
I haven't heard any 4th gen songs being played yet.