>>103475482 (OP)In no particular order, these are the nine Pillars of Hololive. There are other talents with respectable numbers or occupy different niches, but they can be replaced over time. If all these nine are gone without anyone big enough to replace them, Hololive will fold.
>Streaming GiantsThey stream everyday and like to host big events that could tie the talent pool together. Without them, Hololive will just be another idol group.
>Social ButterfliesFriends with literally everyone. Them leaving could cause a large chain reaction of other large talents leaving.
>Masters of their CraftIrreplaceable talent and reputation. Even if they're not the biggest vtubers, their effect on the cultural zeitgeist is disproportionately large.
>The CanariesIf they leave, especially in bad terms, then the upper management is compromised and the brand will die. Years of goodwill will disintegrate overnight.