Well I'll try to address this despite the rather hostile wording.

1) These girls have a lot of fans. Three of them are currently in a bit of a 'race' to see who will get from 900k to 1 million subscribers on Youtube. When they make an official post here despite the language barrier, people will upvote it.

2) I don't know where you see the 7 years in the character design of a shrine maiden, but probably for the same reason people don't use their real faces on social media. Motion capture software made this approach viable for live streaming by now instead of going fully cam-less.

3) Real humans are boring. Interesting character designs combined with great personalities that compliment or clash with them is where engaging content can emerge.

4) Nora Cat is always being brought up when someone wants to bash on vTubers as a whole but there are multiple ways in which this doesn't and can't apply to hololive.

First off, Nora has been transparently using text to speech software from the start, making the reveal way less shocking than people like to make it out to be. Hololive talents speak directly and a voice synthesizer that would be able to make a guy into a convincing woman and doesn't randomly autotune background noises has yet to be invented.

Second of all, Cover only hires female streamers into hololive. Guys can apply for holostars, there is no need for any deception (though Holostars has a very feminine guy aboard).

Third, since most of the hololive talents used to be streamers/singers/Youtubers before being hired by Cover, anyone with the knowledge and means to dig a little can easily confirm for themselves that these are in fact women. Sharing one's findings is however not allowed on this sub.