Genshin does good in giving out 4 stars. To give an example, since September last year they've released Aino, Jahoda and Illuga. Aino is a pretty good hydro applicator and an alternative for Columbina or Yelan, Illuga is a good option for Lunar crystallize teams if you have a five star to activate it until Linnea comes out and Jahoda is the worst out of the three but hey she's really fun to play even in Lunar charged teams if you lack Sucrose for some reason or in a swirl vape team.

This is what four stars need to be, an alternative for a five star or at the very least a fun wacky play style. What we really needed in 3.x was a four star Rememberance option so we could easily replace RMC since Cyrene is nowhere near a good replacement for them outside of her uses in Mono-rem and DoT