Riot has made this game into gambling to exploit gambling addiction
Its so clear to see now. All the choices made have been toward taking away as much ability to move as possible.
To keep you stuck in the same place for as long as possible while giving you the hope that you can actually accomplish something.
They realized that they can manipulate players into playing as long as possible by making the games as random as they can. That way you never win too much, you never lose too much, but most importantly you become addicted to LP.
Losing streaks -> You keep playing because you want to get yourself out of the hole Win streaks -> You keep playing because you feel like you are finally getting better to move up (aka "the high")
But in the end, it's not up to the average player.
What are the purpose of the pros? To fufill a very important part of gambling addiction: the proof that its possible to win.
Professional players that do these amazing climbs are essentially the guys that climb up those unstable ladders at amusement parks. Is it possible? Obviously yes, I mean that guy is doing it right there. Is it fair/balanced/likely that a normal person could ever do it? Absolutely not.
All of Riot's decisions are geared toward nothing but keeping you around. Keeping you playing. Spending more LP. Watching more LCS. The problem? They don't want you to keep playing because you enjoy it, they want you to keep playing because you're addicted.