>>65338591I saw someone claiming Youtube changed stuff between Midnight Mission and Xion coming out. The idea was to combat K-Pop bots once again, so obviously they don't tell what exactly they did, but probably limited the amount of views a single user can give within a day. Music with small but dedicated fanbase such as vtubers got caught as collateral damage.
There was also some kind of change a year or at this point two ago. Numberfags used to point to Zuttomayo's channel as evidence, as you can see their views plummet despite it doing more or less the same on Billboard charts. However, I'm not enough of a numberfag either to try to divine the workings of Youtube.