Had to note there's been SO few Asian actors on the market, historically. And I don't think it's all because the market didn't want ethnically Asian actors. Those in the market got work, a lot of it, even if they're not title roles. IMHO "yellowface" often comes out of necessity after having difficulty finding Asian actors.
Other notes:
Firefly is supposed to be a Sino-American fusion world. They sometimes break into Mandarin when swearing, as if it's their native tongue. But there are no Chinese, or any Asian ethnicity, in the cast. None. Ever. I played "Spot The Asian" for awhile rewatching the series, I thought I had one mixed-descent, but hunted down his credit and saw, no, he doesn't appear to have Asian ancestry. Kaylee was supposed to be a Chinese girl, but he couldn't find the actress he wanted.
MASH... couldn't get a single Korean actor. They went with Filipino and called them Koreans, they used Filipino Patrick Adiarte, who played Prince Chulalongkorn in *The King And I, as the Korean "Ho-Jon". But they also used Japanese-American Pat Morita, who had a strong repeating character.
Charlie Chan. Was originally played on-screen by Asian actors, with limited success. Then they cast Swedish actor Warner Oland, who claimed some Mongolian ancestry, but that was apparently a lie.
After Oland's death they recast Chan with a Scotsman, Sidney Toler, again successful.
Not sure what to make of that. The industry DID set out trying Asian actors, they didn't sell. Maybe they just weren't good actors. Or maybe the public's anti-Asian sentiments couldn't handle an ethnically Asian actor... but oddly, they went to see a Chinese-American character lead.
The Charlie Chan series DID use Chinese-American Keye Luke as Chan's son, he marketed well.
You know, I always thought it so strange that Charlie Chan was a brilliant, perceptive leaner, yet never learned fucking English. English syntax, not able to adapt. Must to use, staccato, cadence. Definite, indefinite articles like fleas on dog, must to be scratched off.
It's worth differentiating ethnicity and culture. Pat Morita was born in California. He had no native Asian accent and in fact didn't even speak Japanese. He was as much "yellow-facing" the Mr. Miyagi role as anyone.
Keye Luke was at least born in China, but he grew up in America and had no accent.
China doesn't have a Hollywood-like acting tradition. It's a solid theory that cultural Chinese simply don't have suitable training for theater. Pat Morita, Keye Luke, etc are examples where Hollywood didn't have a problem with Asian ethnicities... but the great majority of successful Asian actors were western-raised Asian ethnicity.