Two things: First, you're in gold, and from the looks of it you play really strong early champs and have good stats on them (props to you, I'm way worse mechanically than you) so in silver you probably would stomp the living hell out of people. Problem with that is it means that at your level of mechanical skill you can easily win games without knowing how to end the game against better players who can hold you off somewhat, and it means that you can probably win silver level games w/out using your team at all. Second you're on that shit elo cusp. Every section that has 5s and 1s is a mix of the 1s trying to get into the next bracket and the 5s who may be trying to climb, but may also have reached a division they are comfortable w/ and found it hard to move past 5 so they stopped trying. It's the one big issue w/ the ranked system, when you don't care but are still around that skill level it can mess w/ people and their promos.
My suggestion if you want something useful to climbing (I'm shit at this game but finishing a master's in educational psychology so I can speak pretty well to the mechanics of how to get better and learn something) is that you look at your games in terms of when you you are losing? My guess is you win WAY more games the shorter they are, and lose more often in long games. The champs you play make this likely, and it may mean that if you want to move up you either have to learn how to dominate lane even harder, or get better at transitioning that pressure in lane into global pressure or helping your team end faster. Another option or suggestion that may hurt your wins in the short term is to practice things that scale hard. You have good mechanics or you wouldn't be strong on lee sin or riven, so if you look into stuff that scales into late game you could use those mechanics on something like azir (not sure what the top lane or jungle version would be) to make it far easier to win late game rather than falling off a bit w/ what you play now and becoming more reliant on team play.
I hope that was helpful and you don't just instantly dismiss it because it comes from a silver (recently was bronze) player. Also if you're around the MMR you should be in terms of skill at what you play then probably 40% of games you'll win because of your team even if you don't play well, and 40% of games you'll lose even if you do play well, and it is about winning as much of the 20% where your play can be the deciding factor as you possibly can if you want to climb.