By 'mainstream', I mean that Vtubers like in Japan would be on the morning talk shows, be featured in advertisements on TV, have shows about V-Tubers on TV (there is a light novel with an anime adaptation called VTuber Legend: How I Went Viral After Forgetting to Turn Off My Stream), collaborations with V-Tubers and sports teams are a common occurrence, and while we have had some of these things in the West, it's not as pervasive as it is in Japan.
In my opinion with Western media being continually ass, it's only a matter of time.
Zentreya probably being a guy aside, text to speech streamer is fucking annoying, especially noticeable during collabs, always 10 seconds late to the conversations and volume too low and flat to make impacts
I say Zentreya is an exception as chat uses that delay to set up some FANTASTIC one liners and gotcha responses. So again comes down to personality as like Alex Jones she accepted and embraced the meme.
I thought Zen was a dude too until multiple streamers have talked about meeting Zen IRL, so I'm just gonna chalk it up to extra shyness, because it doesn't really matter.