I don't think there is a lot of space for asian pornstars and only a couple get the limelight (Asa Akira, Kazumi, Lulu Chu, Vina Sky)
Asa is one of the most willing pornstars out there willing to do A LOT of things on camera and that helped her gain fame.
I think Kazumi just knows how to use social media really well and is for the younger generation.
Ember is about in the middle and having a solid career. It seems she actually likes what she does too. Fuck a Fan + other things and brings passion to every scene.
I think she's had a very solid and long career which says a lot about her and she shows no signs of slowing down.. and also fans have more interest in her than ever before. Very hard to do in the porn industry!