Last season, I climbed from Platinum III to Diamond V/Diamond IV three different times after decaying, on three different roles: the first time with jungle, second with middle, and finally with ADC before the season ended. I've been Diamond in every season prior to this, even if most of the time I decayed before the end of the season.
This season, I'm stuck in low Platinum with <50% win rate in all roles, and I'm struggling to have literally any impact over games where team mates are feeding, even with champions I've historically had 55-60% win rate with in past seasons.
130 games into the season, the only mid lane champion I have positive win rate on is Lux, and that was primarily due to a freak string of 15 games with teams that didn't put the game into an unwinnable state within the first 10 minutes.
I have zero impact over the outcome of the game, because even if I win early in a losing game, every other lane has already fed the enemy just as much as my opponent fed me. For example, games like this:
I have 100% kill participation in a 20 minute game.
The jungle fed and left the game; in fact, their match history in the past week has 7 leaves.
Top and mid were combined 0-7-0 until Taric and I gave up bottom lane to try to recover the game.
This is literally how every fucking game this season plays out, win or loss. There is no variation on it. One team has multiple lanes feeding the shit out of the enemy team, and then the fed champions just steam roll over the losing team with so much gold advantage that the losing team can't contest anything.
It doesn't matter how well I play; even if I'm playing jungle, the losing teams' lanes will start feeding on their own 9/10 times, without the enemy jungle's intervention, often before I even hit level 3. If I'm playing a solo lane, chances are they've died 3-5 times before I even hit level 6.
This is actually out of control. Last season felt bad, but trying to win games in this season is hopeless, thanks to the comeback mechanics just being more sources of gold for the winning team, and not actually doing anything to facilitate comebacks when one team is up 10-20 kills.