At just shy of level 170 I have been patient with this game and it's design flaws for a very long time now and put up with a lot of very poor design choices because I could see the potential this game had if only handled properly. I also saw that the developers seemed very active and passionate and that gave me faith that my patience would be rewarded eventually once the devs started really improving the game. The matchmaking changes made in the latest patch 13.0 have me finally genuinely ready to quit this game and never look back.
I never minded mentor matches when they were still broadcasted, I wasn't one of those players who cancelled out of every mentor match to avoid playing with noobs. Everybody is a noob at one point and it's important to remember that and be willing to spend some time helping carry them through their first terribly awkward steps into this game. Let me emphasize one part of my last sentence however: SOME. It's fine to spend some time helping noobs but when 99.9% of your queues turn into exclusively noobs constantly feeding elites/antagonists, not understanding objectives, or not even understanding their characters and the most basic mechanics of the game it becomes a horrific experience trying to just log in and play for fun.
I have no issues at all with still getting matched with a low level team occasionally, heck, even half the time. But as of 13.0 it has genuinely become a matter of knowing for a fact that whenever I log in to play it's exclusively going to be losses, frustrating drawn out barely wins, and having no hope of ever just having a fun match where things feel even remotely fair. You are simply punishing veteran players who have put the most time and dedication into your game and it isn't helping to improve the new players at all. If you drag a level 5 into a 45-50% mmr match they are going to spend the entire match getting slaughtered and hating it. The number non ranked or tier 6 players I've seen disconnect mid match only to never log in again has skyrocketed because you've created a system where both high and low level players alike both become much worse off and have much worse playing experiences due to being forced to play together. The previous system wasn't perfect either but you tried to fix it and broke it far worse than it ever was originally. I'll still log in to play only if my friends are on to play with but I'm done with random queues period until this changes.