why does ranked get worse the higher you go?

people in ranks below plat actually try their best to win and will not throw the match if something doesn't go their way 99% of the time, while in gm you have people doing the most random thing while also instantly deciding to throw the match as soon as someone bans / takes a character they like most of the time. How are you even supposed to reach celestial without 6 stacking? I really feel like diamond and GM is filled with infants while bronze, silver and gold is filled with people that has a functioning brain