Makes you wonder about all those VTubers.
VTubers are almost entirely in the voice. I've never been into VTubers, but when friends I have exposed me to them, they all had extremely feminine voices, which is pretty hard to fake. Not impossible, but even skilled falsettos, you can usually tell, and they have a more limited range than VTubers tend to display.
As best as I can tell, a strong dose of femininity is the single most relevant aspect of what brings interest in VTubers.
Hololive and Holostars are definitely female and male respectively. Besides there being videos still out there of quite a number of the Hololive girls from before their joining Cover, it's a hiring requirement that Hololive and Holostars applicants be actually female and male, respectively.
Plus, on the JP side of the Vtuber world, male Vtubers who use female avatars are open about it and have an actual term for it, babiniku (short for virtual bishoujo juniku [
bachuaru
bishoujo ju
niku] or virtual pretty girl incarnation. Examples of the ones who use voice changers are male illustrator ukyo_rst (aka VTuber Maoh Magurona) and the author of No Game No Life,
Yuu Kamiya (he uses the same name for his VTubing). Examples of those who DON'T use a voice changer are Note Takehana (illustrator for LN and recent anime The Hidden Dungeon Only I Could Enter) and the duo Rimu to Maki (who are Rimukoro, the creator of The Helpful Fox Senko-san manga/anime, and Maki-hitsuji, one of the illustrators for Azur Lane). Can't say anything about Western VTubers though.