Gold 3, soon to be gold 2 player here. Last season i was hardstuck bronze, ending season 7 at b2 and starting s8 at bronze 4. Guess what? I got out of bronze in about 30 games once i learnt basic macro and micro. I'll provide you guys with some tips - these are not cure-all "win every game through knowing", because there's no such thing beyond a lack of ignorance. The more you know, the less you'll make mistakes, but you need a bit of real skill to make plays and get leads.
The thing you're talking about is actually the opposite, the higher you get the less you can climb with a bad team, but it doesn't feel like it yet because of the whole 'grass is greener on the other side' mindset.
In bronze, if you're really good, you can 1v9 and utterly shitstomp even if your lanes throw. Because people don't know how to capitalize on a winning lane.
SO, If you get a winning lane, exploit it and win;
That's part 1, abuse your team's strengths. If a toplane renekton is 2/0/1, roam or gank it and make that a 10/0/4 or something like it. The enemy will have a significantly harder time dealing with it the faster you can accellerate his lead
If you play jungle, camp winning lanes super hard. The more ahead 1 person is, the more more ahead they get by the minute exponentially if they play right. Thats snowball for ya
Part 2, is macro.
that people are exceptionally bad at doing anything but deathball strategy to punish a winning player. This is when macro matters.
If you're splitpushing toplane one minute, then rushing through the fog of war to get a sneaky dragon on the botlane, they might try to send 3+ top and then you can either get the objective or kill the stragglers.
So, if YOU are the winning lane, never let up and assault them with so many quick bullshitty attacks that you spread them too thin and then rush the towers and objectives
Part 3, learn your champions.
This is some super basic shit that a surprisingly small amount of people understand.
Pick a tiny champ pool for your main role. Pick 2 major champs you want to get really good at, get 2 that you'd be comfortable with pocket picking if your team absolutely needs it, and also learn an even smaller champ pool for other roles - 1 or 2 champs max. Focus on your main role, get so good that you're winning or at least surviving lanes that should be countering you hard, and you'll climb fast
And finally
Part 4:
Don't be heavy.
If your team is winning top and bot, don't be inting mid, basically.
If it means you have to play so boringly safe that you have 40 less farm than your enemy and can only barely stay within a level or two of them, then do it. Don't slip and make a 1v9 beast on the enemy team who can do what you can do when you're fed.
TL;DR for the impatient:
Snowball winning lanes - They matter more than trying to salvage losing lanes
Outmove the enemy and relentlessly spread their attention so you can sneak objectives and kills.
Learn to play a small group of champions the best you can possibly play. The more you try to bite off, the harder it is to chew into digestable information.
And finally, Let your team do the heavy lifting when you can't do it yourself. Or at least, don't make it impossible for your team to beat the person you're losing to if you 5v1 them later.
Best of luck
It never gets easier, the only thing that changes is how much more efficiently both teams do the same things i mentioned.
-AA