Can we make a mode where you can play only your mastery 5+ champions pls ?

LoL's never been more toxic than now. You go in ranked and you find toxicity. You go in normals, practicing your non-mains / new champs, to chill have fun, do off-meta stuff and you stumble across the 'tryhards in normals' and still find extreme toxicity. When you call someone tryharder - he insults you back or states he doesn't understand why tryharding is bad. Well it is NOT bad wanting to win, but taking advantage over players who bought lets say Draven 2 days ago and want to learn him, with your main champs, dominating them in lane and then say ggez. Not only that, but the team of the more inexperienced player starts insulting him, calling him feeder, noob, boosted .. etc. I understand we have practice mode now, with some hitting dummies, we also have bots, but let's be real be here, best way to learn your champ is to play him vs other leaving decision making creatures, not some AIs. When you tell your team "Well I'm still learning name of champ", they say go with AIs.. this is so dumb, because AIs wont make you master the champ.

TL:DR - In order to avoid 'why do people tryhard in normals' topics and maybe reduce toxicity a bit, I believe creating a mode, exact same as draft pick, but where you can ONLY pick your mastery 5+ champions, heck i believe it should be implemented for ranked too, so all those 1st time champ name kids can stop ruining your ranked games.

I'm sure this won't stop players who want to feel almighty and powerful by picking their mains and dominate 1st timers in normals, but I'm 100% sure it will reduce the quantity of them and provide fairer experience for player who want to chill and players who want to 'tryhard' with their mains.