Okay, quick forum history lesson.
@superduper joins the forums a couple of months after the forums splinters from the Kiwifarms vtuber thread, and stands out from the crowd by having a huge, illogical hate-boner for Phase talent Himemiya Rie. Now, Rie hadn't really done anything to deserve that level of ire, besides maybe express a slightly left-leaning view in an industry dominated by 18-35 year old women (aka a group that tends to lean heavily left). Forum sentiment gradually went from "what's your malfunction" to "here is Rie content for you because we know you hate it" to "Superduper is Rie". Superduper went from huge Rie anti to huge Rie fan (superduper claims the content had improved but it's hard to see it). These days, superduper doesn't talk about Rie too often, and just reads forum posts that are several months old and occasionally posts about some indie and most people ignore those posts because superduper hasn't really bothered to put much effort into recommending them.
Now we have background covered, what is Rie actually like as a streamer? She's got the technical stuff sorted - I don't notice too much in the way of scuff or jank when I watch her streams. She's really good at engaging with her chat, especially membership posts and superchats. She doesn't have too many unscheduled breaks and doesn't start late often. She's a good singer, as long as you don't mind that she only sings asian pop music. If you want to join her channel, she has some pricey membership options if you want to request content, but you get plenty of streams for free. She's even buying a new apartment, so it sounds like her audience really likes what she's offering.
As to whether she's actually good or not, I can't really tell you if her brand of mental illness is going to suit you. Lia and Pippa are much more to my tastes, for example, but that's not to say Rie is bad, more to say my preference in streamers isn't quite with her. Sometimes I don't mind her content, but I wouldn't say she's a favourite. But maybe she suits your tastes. That's something you best decide for yourself.
But it's defnitely fun to make memes of Rie like she's the worst thing to happen to vtubing.