People in ranked

See this is the problem with no tribunal anymore. I just got out of a game with a Cho that helped the team first half of the game, mid game we had a team fight and won, then he didn't want to help out in fights, full tank Cho'Gath was just sitting back shooting Q's not wanting to do anything but sit back with the adc or not group at all. i was playing Yasuo so all he had to do was engage and get on back line with our thresh and we would win the fight. and this is y toxicity exist so badly in this this day in age, because you get people like this who you cant get banned for trolling anymore so they have free willpower to troll and then the people who are nice and having a fun time in the beginning get all pissed off in the end. Especially in ranked its the worst, in norms there is no reason to be toxic, but riot is not doing anything about the trolls and people so yea there will be toxicity in ranked. Now i understand being toxic is wrong and its against the summoner code, but lets be real toxic people get banned while trolls don't makes 0 sense. I have seen way to many people get away with trolling in ranked while i have personally had 1 account banned for being toxic, but if we lose the trolls in ranked what is there to be toxic about. wouldn't that lower the toxicity a lot in ranked?