My first 10 games as USF were all wins. Out of those 10 games, I carried 8 or 9 of them (and I was a worse player back then). After those 10 games I got the rank of ~480 if I'm not mistaken. I proceeded to carry games up until rank 300. After oscillating around rank 300 I slowly but surely started improving my game and adapting and reached rank 100 as USF in 3v3 only random.
All those MM fails and leavers and crashes work both ways.
I've literally had a losing streak of 9 games where in each of those 9 games my teammate either left or joined but were afk for 10 minutes -> can't surrender -> have to leave
I've crashed on won games, crashed on lost games. Although after the 64bit patch, I seldom crash.
I've had MM fails where I got paired with rank 5000 and wondered why I'm playing 2v1 when I check the ally base to see mass retreated IS spam, no AT gun, no vickers and I figure, amazing.
However, all those things happened to my enemies.
I've had games where top 10 axis players got paired with top 6000 against an average rank of 100 in my team. Meaning that the games were laughably easy.
I've also had games where the enemy crashed and we turned a losing game into a winning.
I've also had games where I had a winning streak of 3-4 games purely by random enemy crashing on load screen.
So in other words:
"God giveth and God taketh away"
Statistically it all evens out and I believe that by being top 100 for more than 2 years now proves the point that, while ELO hell exists, it's not inescapable.
Again, I ONLY play 3v3 RANDOMS as USF. I play OKW mostly custom games here and there on random maps with random people and OST/sov/brits if I want a nice calm 4v4 with expert bots (eg. 20 panthers minute 13 on Lienne and USF "expert" bot charging them with HE Sherman or Brit "expert" bot placing a mortar pit on middle VP).
You win some, you lose some. The point is that when you get into a 3v3 game where you're the outlier (recently had such a game, 2 easy bots on my team vs 3 easy bots on the enemy team, PGren blobs, 222 ultra spammers, penal spammers, etc) you need to show skill and carry. You NEED to push back the enemy in your lane and flank to help your bot teammate.
Examples:
.
.
.
.
.
.
.
.
.
You win some of those rank MM Hellspawns, you lose some. Sometimes I get paired with 2 mouthbreathers, sometimes I get paired against mouthbreathers. Point is, if you're good, you'll get where you want to be.
EDIT:
ALSO, never leave games. CELO is a cancer and doesn't paint the whole picture. Uninstall it. 3v3 or 4v4, doesn't matter, never leave games until you see they are unwinnable. I've played against top 100 mouthbreathers and I've played with rank 800 exceptionally good players. I've played against top 50 premade teams that had the skill of a boiled potato. Great teamwork, but poor individual quality. They knew how to coordinate and throw stuka sector + zeroing + offmap arty to completely deny 80% of the frontline but when it came to micro skill -> EXTREMELY POOR.
Don't leave games.
Want an example of a great coordinating top 10 premade team that is just abusing one meta?
If the abuse fails, they lose. I owned OKW Gardening Lelic in Lienne town part of the map even though he played triple SPIO with flamers (abuse of spio strength and town part of map CQC), flanked to help out my teammates (who are also premade and EXTREMELY BAD) and they just ragequit all 3.