It’s the magic of marketing.
K-POP and entertainment industry was introduced to the westerns in recent past years. So Korean beauty standard like pop idol is the new goto but it is unrealistic if you see them in person you will see how pale they are like a paper sheet.
90’s pop idols have a normal asian skin tone and in late 2000 girl group idols was gaining more popularity so it set the new standard now every boys and girls have to be super white.
And there’s a chain of thought that says if you are pretty you will get a better job and better life. So their commitment to the crazy routine is a must do.
As for skin aging i blamed it on genetics as i am asian in my 35 still no line of wrinkle while my western friends had in their 20.
most Korean products are nothing special, if you take away the marketing and story line out, Sulwhasoo is just a high price moisturizer. but they have wide range of products from light to heavy you will likely to find one that you like.
i personally like Japanese products more because they did some researches and papers on their ingredients more than just throwing some extract in.
Many Koreans use western products such as Estee, Lancome, La mer…as well
to this “What is it that koreans know and have, that we don’t?”question
IMHO consumers are humans, human always want new things, even big companies still have to launch new series.