During my misspent youth I spent a few years studying Chinese boxing. The defenses I learned against grabs (arm grabs, shirt grabs, etc.) were quite useful and valuable. Everything else, not so much.
I find it very misleading that people point to these Youtube videos of an MMA fighter beating a “Kung Fu” Master. The fact is, whenever you have a professional fighter against someone who is not a professional fighter that pro will generally win. This is the same game the Gracies used to grow UFC, they were all professional fighters against people who were not. It’s never the style that determines the fight but the person. Also, if they allowed eye gouging, biting etc. these fights might be different.