That’s not true at all. These are concepts that are dated. Asian women all know that they can and should work out to improve their bodies. Asian guys look very positively on girls that take care of themselves. The issue is that asian girls usually don’t feel like working out and it’s not something the culture puts a strong emphasis on. Obviously, I’m not talking about women that work out to the point of becoming men.
Asian American guys maybe.
Japanese, Korean and Chinese guys - 9 out of 10 times they will pick a Woman with no ass, rail thin, prioritizing still a pretty face over everything else and breast size is secondary.
They are not interested in a "Amazon" Woman type that is popular in the Americas.
You say it's old and archaic. Well there's a lot of old standards that brainwashed young people continue to observe today. Especially in China where media diversity is limited so your primary influences are friends and family.
When you look at a societies media it often is a catch 22 that determines the preferences of that society. Reality TV shows and variety shows mainly show "Racecar model" girls as the desirable archetype in China. These girls have very low muscle volume or fat. Just the bare minimum muscle required to do their job.
When you have sex with these types they have very low stamina and can't take much thrusting. Very weak pelvis and if they have a baby 99% of the time they'll need an epidural, C-section. And a lot of times the baby is premature because they have virtually no muscle or fat reserves to help carry to full term.
Over time as I mentioned before neotony has been the selective genetic preference in East Asia which lends itself towards physically frail Women with facial attractiveness but not much else brought to the table. They are not intelligent either because their mother had low ALA/EPA/DHA reserves during pregnancy.