Dude, don’t start comparing BTS to The Beatles, Michael Jackson, or even Elvis. My God. It’s not fair to them. Sales metrics (which this board loves) will make them look silly. Their international success is to be admired. In terms of their success as a global artist let’s wait a few more years and see what the numbers say.
Times have changed and digitals are quite important too (although in Korea BTS still has one rival remaining).
BTS will be the best selling artist of 2020s and Adele is no longer selling that much anymore.
So for all practical purposes it has become the greatest in the world except Korea itself.