Why not just keep dynamic que and add duo/solo?

I like to play this game to play with my friends in a competitive enviroment. Problem is we always seem to have 4 ppl on at a time. Now instead of being able to play ranked.. regardless if its flex que(cant que as four for flex. could in dynamic) now we have to play normals and i personally dont enjoy those as much. Wish we could've kept dynamic and just added solo/duo and had separate ranks for each as they do now.