So, I've seen a lot of complaints about being in "elo hell" and how they are being held back by their teammates. My first reaction was to look them up on Op.gg, to check out a couple of statistics. All of them were between silver V and Gold V, which is by most standards considered low elo. I saw a couple of trends that really hold back players at this elo (aside from the bad mentality, and not owning their mistakes), mainly the Cs numbers which were on average around the 4-5cs per minute mark. Now, in most games it is very very very easy to get at least 7cs per minute, which is a huge amount of extra gold. 2-3 cs per minute more, can result in a good 600+ gold for free. 7cs is pretty baseline, for laners (excluding Jungle and Support), and should be aimed for almost every game. Sometimes it is indeed okay if you have less than that, but in those types of games, you should have compensated by getting objectives, extra kills, or just pressure in general. Ultimately you should aim for 10cs per minute if you can, as this will result in a huge lead that will most likely take your opponents by surprise. Having good cs is not about greeding for cs that will get you killed, it's about getting everything that you can, whilst remaining safe. If I am zed and I can't tell where the jungler is, and I have no wards left, I don't go playing agressive and basic attacking minions, I Q them from a safe distance.
The second thing that I noticed was the abosultely terrible builds, that are a waste of gold. This also goes hand in hand with the bad rune pages that hold many players back. If you don't use your rune page to make you as strong as possible, and if you don't optimise your build for your character, there is no way you'll be able to carry. Ask a Challenger player to climb to Challenger from an unranked account, whilst building Ap Zed, and they will tell you that it is most likely not possible.
The third thing that seemed to be lacking was consistency. Some games the people went 18 6, other games they went 0 11. You don't have to play a risky style to climb, you just need to iron out mistakes and captialise on the enemy's mistakes. You don't have to chase someone for 2 minutes instead of doing Baron, so you can boost your KDA, if you want to win then make the right decision and weigh up the different options to eventually destroy the Nexus. If you want to play a bloodthristy free for all, play an FPS .
Finally, learn from each and every death, be proactive and don't make the same exact mistake. Ping your team to take objectives, and use your brain instead of your emotions. I'm sure that you can climb, but focus on what YOU can change, instead of how bad your teammates are. Your teammates are probably bad, for the same reason that you are, because they are blind to themselves and unwilling to change.
If anyone would like any help, or wishes to ask me a question, feel free to add me in game or post your questions here. Good luck in ranked, and happy new year !