People had said like a year+ ago there was a close correlation between China effectively banning kpop on the mainland and the debuts of Luxiem (literally the ban happened like 2 months prior). There happened to be a glit of Chinese kpop stans looking for something vaguely similar that also wasn't banned and voila, here comes Luxiem, a group of exotic hot foreign dudes (only anime).
All this time, nijiEN (and even holoEN later) were chasing a mirage, something that was literally right place right time for a deluge of extra sudden new fans that just would not come about again. And now we see it straight from the horse's mouth. we had been saying this for like a year, nijiEN dudes were never actually that popular in the west.