I made this video about the reasons why I personally switched from a Sigma 35mm Art to the Canon Rf 35mm f.18. My points are designed mainly from a view point of a photographer and part time use for video. As a hybrid shooter, the canon RF 35mm makes a lot of sense for the Canon mirrorless R system. Besides an opportunity to save some money and getting the native RF mount benefits, it is smaller and has quiet auto focus and good minimal distance focusing abilities.
RF VS EF mounts