Well, just from your example, aight.
1) Your exact words were "I won my lane." Good for you. Well done, too bad the other lanes lost. Too bad you couldn't, well winning your lane, leave lane and go down to bot kill or force the enemy adc and support out of lane, alleviating some of the pressure on bot and helping them get back into the game, and maybe even pick up a kill yourself. Then head back to top, which you've been winning, and your opponent will likely now have caught up with you (because you were winning and they were behind)
2) No, if 4 people want you dead you are not dead. Or, at least not where it was worth getting you. These's these fancy little items called wards. And if you want to win and you are destroying people, you'd better expect the enemy to want you dead. So you'd better have these handy little items down in the river, and probably in the entrances to your jungle. NOW YOU CAN SEE 3-4 people coming to kill you and you can not be there! Or, you can now make it so that you trade 1-2 people for you. This was not a good trade for them. And then you TELL the other lanes, in no uncertain terms, TO PUSH. Get 2 kills and 1-2 turrets for the price of you and one turret.
High ELO players are not lucky. Wingsofdeath lost 4-6 of his placement matches when S3 hit and, guess what, he's Plat now. And you know what? He really didn't care he lost those games. He even said he didn't care. High ELO players have the KNOWLEDGE to consistently win until they are at the ELO they belong at and the SKILL to apply that knowledge.