Why is the game balanced for high elo but taught at low elo?

It's been something that's been consistently on my mind as to why the game is balanced for the top 2% of players when the game is taught at a level that most players can't even grasp simple concepts into the game. One thing I repeatedly run into are teams who will continue to fight over and over again after they die each time and brings me to think , why do people not understand that the game is based off gold? Why isn't it almost beat into players heads that once you die you gave the enemy gold and you are now in a deficit. My previous match I played draven and tried to maintain my farm but my team would just repeatedly over and over and over again try to team fight when they were down so much gold. It was to the point the enemy team was at 15-17k gold per person and meanwhile my entire team was 7k-10k (with me being at 15 due to keeping my farm consistent throughout the game.) At the end of the game the enemy team started talking down to me and told me "it's okay to blame yourself poor thing it's always your fault." It's just really confusing to me how I even typed to my team such as "Guys stop fighting they have more gold than you do, stop fighting without me etc etc." But all i did was get flamed and harassed back? I'm just at the point in this game where I want to help people learn the game but people literally REFUSE to almost. and it just leads me to think why is the game taught at such a low level of play when balanced for plat+ (top 2%.) I feel if more players were taught how to play at a higher level than what there is now more people would be winning games instead of feeding repeatedly. Then it brings me to think why a game is balanced for the top 2% when that's considered "normal play" of the game. When you play at that rank you play the game as its intended to be played. But the other 98% of players just play it like CoD because they're simply not taught how to play otherwise.