Placements its a joke?

So my first acc with like 200 skins is banned now so i create a new acc. I played solo/duo before preseason came out and now i have g1. I started to play flex 5v5 in preseason and i won 7/10 games with some nice K/D/A. And guess what? I'm in iron1 when im still playing vs plats 5-3 I mean wtf? How that shiet work now? XD I'm not sad but its fck ridiculous. Somebody plz explain me that.

Sry for my English if i wrote something bad don't flame. Love u <3

PS: my nick is a joke too XD