At what elo do players stop doing these noob things?

Recently I've come across some bad ADCs. For examples:

No AD runes at all, but has trash like crit chance yellows and blues, scaling MR blues, etc. And then starts with a long sword. After going 0-2, gets sword of the occult. Doesn't even have any other items at all. And then guess what, we lost.

Graves has 1875+ gold on first back after winning a fight where his thresh hooked the enemy ADC and his lane getting the first 2 kills of the game, opposing ADC only has like 1000. But instead of buying a BF and boots, goes for a pickaxe and berserker's greaves instead. Opposing ADC bought nothing yet, waiting on a BF. But Graves just pushes the lane. Doesn't even try to attack the opponents that are way behind, and they just tank the minions right before their tower and don't even miss any. Then the behind ADC recalls and gets a BF. Not only that, but Graves then loses a couple fights. The next think you know, it's 20 minutes into the game, and he's stuck on berserker's greaves, pickaxe, and cloak of agility, and still waiting for that BF. And then loses another fight and the tower and then the dragon and pretty much lost the game because of this. Good thing this Graves was on my opponent's team lol.

And you might not believe this, but these were from my ranked games and done by players that were in like platinum 3. I would have thought that players that made it that far would stop doing things this bad. Does anyone know how high you have to get for it to stop? I mean I'm not asking for players to play at the LCS level or anything, but where do they not do things on this level of noob? Or does it just never go away because of account sharing and these players weren't even really platinum 3?