The kings were much more alike indies than corpo chuubas, there was little sense of a brand identity in that era and the corpos that owned them didn't release huge waves of talents all at once or organize events and concerts with their logo plastered all over it. Kizuna was always just Kizuna, while most Holos and Nijis are inseparable from the company they belong to. Maybe this is another reason why these early corpos are all but fucking irrelevant nowadays, without any brand loyalty people just abandoned them when they stopped caring about that specific oshi, a casual Holo fan is much more likely to stick around and switch to watching other talents in Holo because of the insane amount of cross-promotion and brand loyalty.
In a broader sense this also signifies changes in the broader community, I'd like to believe that back then everyone was a "Vtuber fan", now people are "Hololive fans" or "Nijisanji fans" or "Vshojo fans", the industry has grown into serious fragmentation and a general sense of dislike between different groups. Indies vs Corpos, Nips vs Overseas, Idoru vs Freedom, Small corps vs Big corps. I think kirsche said it pretty well when she was talking to that logcast moron, there is no real "Vtuber Community" even if I myself like to throw that term around, there is a faint sense of unity in certain things but it's undeniable that this hobby is not some big happy family.