I think the whole confusion and bad feelings comes from the fact that V tubers live in the same space as twitch streamers, just that they have a virtual persona overlaid on them. A lot of people just assume that they're the same, and we're MEANT to believe that, but they're not, V tubers are actors playing someone they are not.
I'll admit that I sort of half fell into that trap too, while I didn't think that Kiara's actually a phoenix or something and I knew that there's a level of disconnect between the character and the person behind it, I did expect there to be something genuine in all of the Vtubers' interactions, and there almost certainly is, which makes for easy confusion. I don't think it's fake when Fauna tells Mumei that she's cute, so why should I be so sure that it's fake when Kiara tells Calli she loves her, right?
Also this might be all the Copium talking but I genuinely still think there's something there, be it that Kiara just likes Calli as a friend or anything. You can't keep your persona up for hours a day if it's entirely fake without it breaking from time to time.