One of the most beautiful FAs that I have ever seen was actually on a KE flight to BKK.
She was not a Korean, but a Thai.
She may not be THE most beautiful FA that I've seen in my 25+years of extensive flying experience of over 60 airlines. But she was still awesome.
Other than that,
I have yet to see good-looking FAs on KE or OZ.
I find them generally friendly and polite, but not beautiful.
I have seen some beautiful FAs on SU,MS, and TG, a few on KL, and several on SQ. Of course, this is my personal taste.