I don't really feel like we need a more mature version of the Sims 4, simply because it already exists for those who want to have it and play more mature content for this game. We have a very talented community of cc and mod creators who have already done some pretty amazing (and sometimes pretty wild) things to add those aspects to the game as it is.
That said, I DO feel that the Sims franchise would benefit from a competitor because it would force the creators to go outside their box I think, creatively. I don't mean to say that the team is not creative. I think they are and love the content we currently have (bugs excepted), but I think having competition would force them to broaden their scope for the game.