So I am a mid tier Gold player and I am at the moment currently playing my 3rd account through silver. My one smurf placed in silver and my main account this season I also climbed through silver. This account was silver 5 maybe 30 LP and it is already Silver II heading into silver I promos without too many games. I use the smurfs to play with friends or do practice games prior doing ranked on my main. That way I can just make sure I am mechanically CS well before going into a ranked game on my main.
I will say feeders occur and sometimes you have rotten luck, but KDA and feeders are not going to occur every game and the chances of you getting bad teammates is less likely to occur with each subsequent game (or rather your opponents are just likely to get them as well).
You need to focus less on KDA and more on CS and Towers.
One of Silver's biggest problems, besides the inability ability to play from behind and toxicity, is that they NEVER take objectives unless they are "free". Meaning they do not take objectives or focus the objective unless it is virtually uncontested (clean ace). They miss a lot of opportunities to take towers and sometimes no towers fall until 20 minutes in games.
They will just continue laning or back after getting a kill.
There is a heavy focus on kills and sometimes all they do is look at the kill count to figure out if they are winning or not.
You may have a habit of not attacking the tower to take it unless it is "free" and miss opportunities to attack and take a tower because you may be choosing to back instead. After you kill someone you should auto the tower or try to take in the mid game.
Looking at your stats you have pretty low CS averages on the all the champions you play frequently and it should be about 40-50 cs higher per game on your leading champs.
I will say if you are not significantly better than silver players (mid to upper Gold or higher) you will have a harder time climbing through silver.
If your actual skill is maybe around Gold V or maybe Gold IV then climbing through silver might be tough, because you will be incapable of carrying bad teammates every game.
A lot of players in silver also fail to exert map pressure. On my smurf earlier I had a game where I was split-pushing and the entire opposing team sent a five man rotation to me. Sometimes I escaped and sometimes I didn't, but by the fourth time of them doing this I specifically told my teammates if that happens do not come to help me just put pressure on the map and take a tower.
A typical silver player would simply say "they got caught" and leave it at that, but after I pointed out that my teammates were doing jungle camps while 5 people chased me around the map they began to focus on towers and even took baron while I got chased down and killed. It took me saying something though for them to change their play patterns.
You also need to say things nicely, which most players in silver don't do. They focus on the mistakes of players and instead of providing constructive advice actually agitate teammates with their comments.
Silver players also have a tendency to want to group and teamfight, but sometimes comps need to split-push, skirmish, or play for picks. Teamfighting might actually LOOSE you the game and a lot of silver players fail to understand that playing into a strong teamfight comp puts them at a huge disadvantage. They just think that teamfighting is the only way to win and its a matter of executing skills.
The reality is that teamfighting with an
into a
is a terrible idea if the game is relatively even.
It is actually even worse to teamfight when you are ahead and you find that your team is losing the teamfights.
You should really consider comps when going into games, always try to exert map pressure, look for towers, focus on CS, and be relatively polite to teammates if you find that your team is losing teamfights or they are making misplays.