Currently there are few other strong girl group like Red Velvet, Mamamoo, BlackPink and Gfriend. But their fandom is not overlap with Twice so Twice is leading alone in digital and physical sales.
Produce 48 will be like the carbon copy of Twice, girl groups from variety shows which will consist of members from South Korea and Japan, their fandom will actually overlap, many Twice fans already like Produce 48 and their line up. And Produce 48 actually will be even stronger than Twice, some of their Japanese member probably much more popular that Twice Jline in Japan, and the rating will be better than sixteen, so their sales probably will be much bigger than Twice.
Will Produce 48 gonna be a problem for Twice? Is Produce 48 is the girl group that will destroy Twice hegemony in Kpop?