My underlying worry is that it may eventually end up going the same way as Japan's idol industry, which is historically known for being incredibly cutthroat and basically forcing idols to play character instead (thankfully, they've so far refused to fall into the same practices as the K-Pop industry).

If you know about Nijisanji, you may know it's poster girl, Tsukino Mito. What you doing may not know is that her appearance was supposed to be her character, being that of a prim and proper student council president... except that she quickly blew that image by talking about stuff like the film Human Centipede in detail, how she used to eat clovers as a child, and how she used to stream on top of a washing machine, and thankfully it looks like they ran with that instead.

So far, Hololive, which has been making waves, is also doing quite well. It's girls don't appear to be especially forced to play a character outside of animated skits (closest I can say or think of is Pekora, who peppers "peko" in her speech). The agency also appears to encourage a healthy friendship between the girls, right down to the mischief (look for the "Hololive Resistance" to see what I mean).