Unfair to mention soaps, most teen-oriented soaps from the UK,US & Oz seem to be cast on the basis of looks from people who have less conviction than a speak your weight machine (especially the one that told me:"One at a time, please"). Some successful film actors are dreadful on stage. Edward Fox and Deborah Kerr spring to mind. I was disappointed by both: they just walked purposely to their "spot" , stood woodenly, said their lines to the audience with no interaction with the rest of the cast.
RtS (whose only acting role at school was generally accepted to be THE worst and also totally inaudible, unlike my normal "Shut up Roger" classroom persona!)