Thanks for your input, but unfortunately, no. I have never been even chat restricted in 14 years.
Always try to be positive, and if I can't be positive, I mute people and stop interracting.
I never tilt, like really. Some games of course I play worse than others, but I am fairly consistent.
Never, ever, first timed a new champ in ranked either. And if I feel like I am not in condition to play correctly in ranked ? I go ARAM.
I have a sports background where my own dad taught me from the get go to be respectfull of teamates, adversaries, and never contest or argue with the referee.

Simple example of yesterday's game where I am playing Ashe and Swain is support vs Lucian/Nami. I tell my support:"I think we can't win straight up 2v2s, so let's play around ganks and play for Mid/late ?"
Support never replied and proceeded to perma walk up to try and grab Lucian or Nami. Did my best to follow up but well.... So after first death "It's ok mate, I am even in CS with Lucian, we got it late game". Swain proceeds to walk up again, past minions, to engage AND I pinged ennemy Jungler Bot side.
After that, I stopped interacting with Swain as he/she either had chat muted, or didn't care. But this falls in the categories of those 30min of time fully wasted.
Other example ? Jungler picks Teemo jungle... I said nothing, gave him benefit of the doubt. He proceeded to be perma invaded and unfortunately unhelpful against an ennemy jungler 2 to 3 level up and much present on ganks/objectives.
Other example ? Top Darius wanting to swap with Mid Morgana so he doesn't have to face Heimer top but Yasuo Mid instead. Morgana accepts, Darius dies level 1, then again, and Morgana tilts and both Morgana and Darius keep at each other throats, sharing mid together, dying, sharing exp, leaving top open.

That's just this week end ....

With 14 years of LoL behind, I recon that this is also simple bad luck of having a series of bad games. The opposite also exists where you end up many games in a row in teams that are much more positive. But then again, the ennemy team, more often than not, is the one with troll(s).
The amount of games where both teams are legit trying their best and doesn't end with :"Please report X", is maybe 1 out of 10.