people seem to forget that this is a team game
dont get me wrong it is entirely possible for one person to lose you the game, but more often than not that one person losing you the game was really all of you losing you the game with the one person as a focal point/the biggest apparent cause. take for example my last game as mordekaiser against yorick. i honestly have no clue how to exist in the same lane against yorick without feeding as mord (ive done the lane several times and every time has had literally the exact same result as this game), and thusly i fed him 4 kills during what technically could be called lane phase, and heres where the teamwork aspect comes in. the reason i said "technically" is because although everyone else was still in normal laning mode, by about 8 minutes he had taken my top tower, and by 13 he had taken my second tower. it wasnt until about 12 minutes, which was when he first was about to take the second turret, that anyone else tried to come top. at this point he had 3 kills, and as soon as our zac came to gank he got a 4th on me and almost killed zac. after he backs and after zac comes and tries to stop him one more time, the second turret is taken. we get one final attempt from zac and lux to stop him, lux dies, making yorick 5 0. at 19 minutes, inhib is taken while bot lane is still in their lane phase, defending their first turret and trying to get theirs.
i should note that while the way i put it may sound like zac was constantly trying to help, this was only after my begging for help for several minutes. even after the first tower was taken his only interaction was saying "maybe you shouldnt be extending like that" (refering to me having just died for the second time close to the middle of the lane). additionally, he and lux only ever came when they thought we were about to lose major objectives, otherwise they spent all their time farming while he was vulnerable to ganks. there was one point where zac literally watched me die maybe 700 units away while he fought gromp, then after i died and he finished gromp he went in and nearly died as well.
i should also note that im not trying to say this game wasnt my fault or that it was mostly their fault or anything of that sort. what i am saying is that this was a good example of a situation that could have easily been either slowed, prevented outright, or even completely reversed in our favor if people werent so caught up in their own game.
people (especially people in low elo) forget way too easily that this isnt just a bunch of individuals playing together, this is a team game. nobody ever seems to coordinate team comps and wind up with teams of all 1 damage type, squishy champs without much cc and with playstyles and kits that dont really synergize well. nobody ever seems to be willing to play for their allies in any regard, wanting only to keep themselves alive and get themselves fed (take for example a game i had earlier today where instead of using his power to help the team our hyperfed fizz spent all his time stealing kills, trying to 1v5, and ignoring the fed enemies and instead focusing the easy, low impact kills). these are some pretty basic things that are arguably one of the most vital aspects of the game. theres really no excuse to have a terrible comp or a comp thats completely countered by the enemy team in a draft pick game. theres no excuse to having someone defending their inhib turret alone while everyone else farms. theres no excuse to not try to work as a team to win the game.