Since Elden Ring is part of the Souls series on speedrun.com (https://www.speedrun.com/souls), why isn't Sekiro a part as well?

I claim to be the most active Souls verifier, multiple games handled effortlessly. You do not seem to run either Souls or Sekiro so far, so your question is from a completely casual perspective, I assume. The community decided to keep Sekiro out because of its differences, successfully giving this game its biggest weakness (not being Souls is insignificant) and also its biggest strength: Sekiro can stand forever on its own, it will never fade out because it has no memey predecessor nor successor. I could also confirm, before the Elden Ring leaderboards opened, how committed to Sekiro the runners are, the true ones at that.