I know what you mean.
I got placed in Bronze I this season, and I easily climbed to Gold V this summer.
Honestly, the skill gap isn't that large. As long as both sides know how to play the game and understand their respective champions, there isn't that much of a difference between a high Silver and Bronze player.
I would attribute more weight to the lane match up rather than player skill in determining which party wins lane.
In my circle of friends, I have quite a few gold, platinum, and diamond players. I noticed that the aspect that sets them apart is simply how much time they spend on League.
Climbing in League takes time, a lot of time. It takes 7 games minimum to move up a division, that is at least 6 hours.
Now imagine doing that 5 times, with some divisions taking as many as 13 or so games.
A Bronze 5 player who does not deserve to be there will need to invest at least 40 or so hours to get to Silver.
Most people have school or work during the day. It would take an average person weeks, if not months, to find the time to climb 5 divisions.
My friends in platinum and diamond almost always have a lot more time to play League compared to me and my other friends in Gold.
Since my high ELO friends play more often, they also get more chances to improve.
League is like a sport or an instrument, the more one plays it, naturally the better one gets at it.
After making the trip to Gold V, I finally understand now that higher ELO players aren't necessary innately better, they just have more time for League.
However, most people just don't have the time to climb higher.