League will continue to get more toxic and less enjoyable unless you at SOLOQ Metrics
You need to add methods of sorting people that are not just wins and losses. The reason people are toxic other than the person whos a real asshole is that you are often times unrewarded for your good plays. If you do well most games you will get a 55 percent win rate+ but often times being 2-0 or 3-0 in your lane isn't enough to make up for your teamates that get caught or go 0-10 and thats frustrating.
You need to reward people for having high cs numbers by 20mins relative to whoever else is in that same ELO. Things like turrets killed before 20, KP, CS, Wards purchased are all small things that add up to what good players do and should matter. These small details will help make the games more balanced and less stompy and one sided
Now to counter the classic argument "people will play for stats". you can't play for stats. Good players will get good stats and bad ones will be unable. it works just like real sports. bad players can't "just play for stats" they are unable to.
this game will continue to be a rage inducing toxic environment untill you make SOLOQ ACtually less "random people hope they are not mad and play together 5v5 Q"
Even Pros and nolife streamers are disliking solo q. It needs a revamp