Honestly, no. Every game is winnable, there is 1/10 that you absolutely will not win even if you pour your heart into that game. I understand the frustration because if you aren't better than where you are currently, it seems like the system is out to get you. Unfortunately everyone gets to points where they reach a plateau and it isn't out of the norm for people to be delusional on how good they are at the game. I haven't had a bot lane win their lane in some 150 games, but i don't complain, because even with that it doesn't matter, i can still win the game because I'm simply better than where i am. I feel like anyone gold and below should just stop complaining about the game and learn the game. This game isn't about kills, or assists, how much farm you get, its about objectives, and you can go 20-0 in lane and just get roflstomped cause you didn't share your power with your team. The proof that you are losing games because of your own lack of knowledge is the fact that smurfs can pick up an account and hold a 70-80% win rate, where you cant even do that on your own. Blame the system all you want, its your own faults that lose you games, not the system. I had a silver try to tell me that dynamic queue was the problem with them losing games, that they always got matched against trios, but i destroyed them on nunu by just taking everything from them, our team was 5 solos. That isn't a matchmaking problem, that's just all 5 of them having less map awareness and knowledge than i have. There is no problem with matchmaking, yes it does punish you for winning 5 games in a row by giving you the worst of teammates for one or two games, but you are gaining 28 LP and losing 10 at that point, you can afford to lose one.
TLDR; IF you are good enough, you will win 80-90% of games up until Diamond, then you actually face really solid players, until then, don't cry about the game, just realize you are bad and start playing to improve instead of playing to get kills. This game is all about attitude, you have a good attitude you will likely win, you don't you will definitely lose.