Eshshshss
"we just randomly populate server ASAP with whomever is available within 1,5-2 tier difference"
As I said, the reason isn't always satisfying. But there it is just the same.
leofrostjc212
Obviously I won't disagree with you about the terrible state of the matchmaker. This season's matchmaking update seems only to have affected the left side of the skill distribution curve. I assume that was tightened up in order to make it even marginally possible for a new player to enter the game without experiencing the crushing matches that you're getting.
So your k/d, kills per match, win rate, are probably not what's driving you into those lobbies. But the matchmaker can't find enough diamond/masters to fill their own lobbies so it's going after the likes of you to pad those matches. There are other stats I believe are at play, though I have no way of knowing with any certainty. It only seems to be one explanation that fits the facts, and it principally involves "willingness to re-queue after loss," but also "amount of time that passes between a log off and the next log on." These are the data that tell them whether or not their matchmaking antics are actively pushing you away from the game. If you typically queue up for 10 or 20 matches in a session, and your sessions are never more than a day or two apart, then the message you're sending to the matchmaker is, "Keep it up. Whatever you're doing is working."
The best advice I can give, by way of putting some of this to the test, is to play pubs-only for a while and very carefully scrutinize the skill distribution curve at the beginning of each match. If your red line is far to the left of the grey bar then you need to actively, aggressively, quit out of those games. Quit out right there on the spot, or quit out after legend selection. Either way you're sending a very clear message to the matchmaker that you won't tolerate just anything. The matchmaker has a job to do and if it isn't doing it right then pubs is the place where you can force its hand. Of course, pubs is still filled with smurfs who range the left side of the curve looking for easy matches, so there's no perfect way to get away from the players you shouldn't be matched against. But this is still a start.
Ranked, on the other hand, works completely differently. The quit penalty means you have no recourse against bad matchmaking, and the very nature of ranked means that the rank distribution they show you at the beginning of the match has absolutely zero bearing on the actual skills of the opponents you will face. I've been in bronze lobbies where people played like streamers because it was early-season and they just hadn't ranked up yet. Stay away from ranked.
And a last note: The longer you've played the game, the more certain the matchmaker is about where it can get away with using you, and the less likely or quickly it will respond to manipulation on your part. I hate to be the guy who actively encourages people to use secondaries because I despise them and the people who routinely use them for no other reason than to cheat the matchmaker. But I don't think that's really the case here. You just need a hard reset and a new account is a good way to get it. Obviously it means leaving behind progress and probably kit, but honestly I'd take a little decent gameplay over any of those things any day.
Best of luck.