>>87802265Nijisanji got to the JP market first. They're still coasting on a small number of huge channels that got in before the gold rush and blew up. Nobody can replicate that success anymore.
Hololive got into the NA market first and struck oil landing during pandemic lockdowns when everyone had too much free time and a chronic shortage of entertainment. Niji was still comfortably successful in that market, especially with their male talents, until a whole series of missteps culminating in the black screen fiasco basically rendered them persona non grata in the west.
There's really no big secret here. Nijisanji got in when vtubing was fresh and new, found a few stars and outlasted most of the other big early channels. They're still coasting on that fanbase. In the west they could have been solid competition but collapsed due to mismanagement and an abhorrent lack of human decency.