Yes korean charts are largely irrelevant because kpop turned into a global music genre years ago. A kpop artist can be unknown in Korea yet still tour around the world filling 10k venues or even more. Why would a company put more focus on one market if you can attract people from all over the world? Besides that YG is promoting BM in korea for this comeback as the group is now complete again.
Any semi popular kpop bg sells more than 350k in a week.