It's crazy in a special way. For a long time, most ID VTubers have always just pandered hard to the EN fanbase. At least, that's what we can observe from the HoloID branch. Hell, even NijiID's most popular members had mostly EN fanbases like Hana and Mika (could be wrong on this one though. Judging it from the clips I've watched of them)
But Kobo getting this fast while having an abnormally high viewership of mostly domestic fans, even compared to most big EN VTubers, might actually encourage ID VTubers to consider pandering to their domestic fanbase too. Or maybe Kobo's personality is just that special and most ID VTubers can't replicate the same appeals that she has. Not really sure why and how she's growing this fast either. I don't watch her at all.
Call me a schizo but I do actually think the ID girls are numberfagging behind the scenes and are looking for ways to try and understand Kobo's appeal. If Ollie's leaked membersonly post a month ago or so was to imply anything, it's that Ollie and at least a few ID members are confused and grew a bit insecure. Not that I think they should. If there's anything worse than tribe vs tribe numberfagging, it's numberfagging within the same agency and the same branch.