>>63490624Different motivations and intentions for being in holo.
Kiara isn't any more disciplined or less lazy than the rest of them, but to her the job is a huge thing. On the other hand Mori is a "workaholic" yet in the first year it was still incredibly obvious she didn't care and was phoning it in, now that she actually cares she's a streaming monster.
Myth happens to have 3 girls that absolutely do not define themselves through their hololive job, so there isn't much of a drive to "deliver", especially not when they don't really lose anything from the minimalist approach.