It is easy to think you are playing good without actually playing good.
In this game:
https://pasteboard.co/HxB1mT5.png
You cared way too much about your KDA that you contributed nothing. You were 0-1-5, so a 5.0 KDA, but you also had only 2.7k damage as a mid morgana. Your 3-9-6 support lulu had more damage than you. Your top and jungler both had over double your damage. You also had 4k gold compared to 6k on support, 7-8k on everyon else. It literally seems like you AFKd that game, being only level 8 when everyone else was 13ish for solo lanes.
In this game:
https://pasteboard.co/HxB2lO5.png
Look at how again your damage is on the low end. The Ryze was plat 4 and he did 33.7k damage, you are gold 4 and did 22k damage. When thinking you should be at a certain rank, compare your stats with theirs at the end of the game and see how it lines up. He had 1k more gold, 60 more CS. Your KDA was good again.. but again... KDA really does not mean all too much in League. People that emphasize KDA, ESPECIALLY in low elo, end up making it so their team is playing down a player.
Now lets look at a game where you won:
https://pasteboard.co/HxB3f3y.png
Notice how the P5 had 60k damage and carried it when you were at 30k? The high gold / low plat vayne also had 53k damage. They also had 7k more gold than you because they were playing the map correctly and their GPM was high. Your KDA was good, but if I watched your replay I could probably point out 20-30k worth of damage that you could have done if you just helped out rather than cared about protecting KDA.
Lets analyze another win:
https://pasteboard.co/HxB4cte.png
The gold 2 kha zix carried with 24k damage. For reference you had 8k damage, the lowest damage in the game other than your team's support and the enemy team's support. In most of your games, as a solo laner, you put out as much damage as a support. Mid morgana can do damage - you are not doing damage because of your play style. Rest of the team was high gold, rest of the team outperformed you.
"Look at my match history. Every single game I play well. Every single game I get teammates who don't."
But this just isn't the case. I didn't discriminate to pick matches, I just took your last 4 games in a row, ignoring your support game since you play mid and not support.