Well tbf teams like 100T just bailed out of CS, and this prompted many to make the move.
plus valorant is a lot "stream friendly" (female agents n stuff) and somewhat beginner friendly, so that's also helping female streamers playing it a lot.
But my main point is - if you grind a game more than EU, you will remain better at it, like EU does not have magic genes for fps., they just have grinded cs much more + better competition there. In csgo beginning NIP helped Swedish scene, which made fnatic stronger in coming years. It's a good cycle.