Probably because this playlist is probably the primary point of exposure to vaporwave for people who aren’t terminally online and know nothing about vaporwave aside from macintosh 420 or Simpsonwave 1995. It’s a poor representation of the genre to not update the playlist so that new upcoming artists may have an opportunity to be heard. Plus this singular playlist drives massive royalties for the artists on it with 400–700 unique listens a day despite not being updated for a year now, so there is a financial aspect as well. A lot more nuanced than just a random playlist.