In French it's Gauche and Droite so no problem here, but every product is labeled L&R because we live in a global market and English is clearly the dominating language. Most consumer product are made in China for the entire world so my guess is everybody understands L&R at this point.
Also, at this point, it might just ingrained in people there is a L-side and a R-side which correspond with their equivalent of left and right even without knowing English. It can be abstracted as consistent symbols if nothing else.