Came back after a year and a half, my experience so far.
So, roughly a year and a half ago, I left League after a MASS series of toxic players became too much, reports were being dished out, however I felt nothing was being done. So I left. I came back about two days ago, reinstalled, booted back up to find everything a bit different, champions I used to play frequently changed around, I started treating the game like I was a new player. But, when I started playing with other folks in Co-Op vs AI, and ARAM I started noticing that the behavior wasn't what I saw all that time ago. Everyone was being cool, and having fun, and laughing and joking about deaths, and stuff. I'm not sure if it's luck that I happened upon certain groups of nice players, or things have begun an upswing. I still have massive reservations about playing the Summoner's Rift Map, but I'm almost inclined to try again. So, I don't know what changed, perhaps the community can fill the gaps in for me. So far though, my experience has been nothing short of fun and calming.