>>918510It works for Nijj because there isn't a strong, english community for them. Hana exists, but she's so seperated from the JP Nijis that they may as well be a different company. Hoshikawa is basically setting the foundation for an english community, like how Fubuki and Matsuri first did when Hololive caught on in the west. It also fits in with Hoshikawa's lore, since she's supposed to be a halfie and knew some basic english before Vtubers were on the radar for EN.
Uto is an indie that's piggybacking off of already existing concepts and leeching off of trends. It works for her because she doesn't collab with anyone else really, so EN viewers see her and check her out because she's doing cute engrish and because she looks like Amelia. She also doesn't have a strong JP audience, so she has nothing to lose from doing so.
Hololive can't do it because it isn't healthy for them anymore. English viewers already have a strong prescence in every stream, and there are so many holos that pander to us every stream, that dedicating yourself entirely to such an effort would only offer a temporary buff before you crash and burn when all your viewers fuck off to go watch Korone or EN again (See Aki, Matsuri and Rikka). Not only does it end up leading to dead subs that will never watch you again, but it leads to losing JP fans that actually give a shit about you.