I have seen significantly less toxicity in the last 2 seasons than prior, perhaps because of the role selection or the ocmmunity generally getting older with fewer newer player entering. That being said, a lot of toxicity is also subjective. For me personally I have a pretty thick skin and though am mid diamond on my main, do occaisonally smurf and play on accounts in lower elo and find the experience not much different.

I think players are just a bit too sensitive to begin with primed by the Riot culture of reporting toxicity over the years making people easily-offended, but additionally I think not enough people it seems are mature enough to simply report and mute someone who is raging. For me personally when someone rages I don't really care, I simply mute them, but I expect them to still play the game at what I consider a reasonable level for the elo. If they start to intentionally feed, afk etc, then I am much more annoyed but still simply report as I can't really change the person's immaturity, but hope not to get them in my games again.