Why isn't champion mastery visible to other players in champ select

It would be allot easier If people fight over mid and one person has the highest rank in one champ over the other person it might ease some arguments for people to notice like oh hey this person can use that champion really well or has a ton more experience playing that champion maybe let's let them go mid but you can only see it in loading screen and by then it's to late and team morale is already down or people dodge and you possibly loose your favorite lane next game.