Mori is way into the "character lore" side of Hololive, far moreso than any other ENs. Kiara is much lighter on this thing and treats the Phoenix thing as more of an inside joke that she occasionally refers to. The two of them developed a "character lore" relationship for their "characters" which was that Kiara was a clingy deredere who loved the death/rebirth cycle and Mori was an annoyed tsundere who was constantly rubbing the bridge of her nose every time Kiara popped up in the underworld. This is a funny concept in theory, you could see it being funny in a fictional story or an anime or something. Unfortunately, the live execution of this concept is pretty challenging when in Hololive there's a kind of "half real, half fiction" element to everything. It's all spontaneous roleplay, so that disparity of "these two are just friends who have good on-stream chemistry" (actual factual story) and "this is a one-sided relationship where Mori may or may not return Kiara's affection, but the point at any rate is supposed to be the comedic effect of the concept itself" (fictional/lore side) makes it hard to grasp either. And naturally, what Mori doesn't understand (she's unique among EN in this) is that fans find the real relationship way more interesting than the fictional one.
They're stuck with the lovey dovey thing, of course, but both of them just consider it a joke and play it up that way. If you actually watched Kiara's streams (which you don't) then you'd know Kiara always talks about Mori like a friend, she specifically says things like she's glad to have made friends, and worries about Mori being too unwilling to open up to her friends, or rely on them for emotional support, and so on. Unfortunately people who clip Kiara adore the Takamori thing so they will take every time she dotes on Mori out of context and explode its relevance, but there are times where Kiara has even had to ask her chat to stop talking about Mori because of rule #3.
I can't convince you to watch Kiara, and I don't even care if you do or don't, if you don't like her. She's an acquired taste, she's not for everyone, I get that. At least go and watch her debut stream and jump to the slide where she shows her "likes and dislikes." Did you notice that in her "dislikes" she listed "one-sided feelings"? They were setting up the Takamori thing from day 1. I honestly think it's clear that Mori and Kiara had talked about it behind the scenes and had the idea for the "comedy bit" but are just clumsily executing it and didn't anticipate that it was going to create a false apprehension that they don't actually get along, or that there's some actual unrequited romantic feeling involved.
