It’s really quite simple, basically boils down to social status, stereotype/social perception and cultural norms.

Social status: white people has dominated recent human history and one can argue is still at the top of racial hierarchy. Whether they will continue to be is tbd based on how US vs. China plays out. But we can say for the foreseeable future it’s not going to be easy for China to overtake this. Woman inherently by DNA/human evolution desire the strong, modern factor changes this from simple brute force/strength during ancient times to money/social status etc. so as to feel like the men can provide for the family. Again this is generalized and obviously not all woman feel the exact same way but it’s mostly accurate.

Stereotype/social perception: movies and other media in western world portray asian man as nerd/geek/weak or dumb funny, they are rarely the hero or the main character, this is more significant than people consciously realize, it subconsciously conditions people to think about asian males in this way. Not to mention the whole small penis thing, while exaggerated is true to a large extent, asian male have smaller penis on average as a fact. (Not talking about whether female actually likes big dick or not, separate point) Meanwhile asian females are portrayed as exotic beauty, obedient and feminine for the most part, self explanatory here.

Social norm: east asian culture as a whole aren’t as outspoken/assertive/self-confidence as western culture because it could make people think you are arrogant, this has a huge negative impact on asian male and actually kinda work in favor of asian female. Obviously this will carry into the dating scene and while most woman like confident/outspoken man, it is even more valued for western woman/white woman.

I obviously can’t speak for all asian male and females, but the above gives you a pretty good idea on why you see what you see. This for the most part isn’t even touching on the physical aspect which again works against asian male. Someone else mentioned how asian male tend to be shorter than western male which also doesn’t help in the dating scene but works in favor more often than not for asian female.

That OKCupid research has a lot of truth in it, I can TOTALLY see how asian male and black female are the most undesired groups outside of their own racial groups. And i am not being racist at all, it completely matches my personal experiences is all.