How comes 4K doesn't work when VLC does?

I've found that often 4K can't convert a youtube video, but for some reason it works fine through VLC. It seems to me that, when pasting a link into 4K, it does not extract the m3u8 link from it and then uses that as the source to convert. Where VLC actually does read the m3u8 info, which can be used as source and successfully convert a video when 4K cannot.
Not sure why that is, but it makes VLC a more reliable converter.