Shun is not archaic, Graham is entirely wrong about that. You can find it in Sun newspaper headlines and articles.
collinsdictionary.com/dictionary/english/shun It's less commonly used than it was, but if you can find it in the Sun then a large part of the U.K. population are not going to blink when you use it. @JanusBahsJacquet the Sun newspaper is
not grandiloquent. You're making incorrect assumptions abut a simple Anglo Saxon word.