So apparently 7 wins and 3 losses = bronze 1

So I'm just wondering, last season my provisionals 4/6 brought me to silver IV, this season I win 7/3 and get bronze I. This system makes no sense to me at all, someone who was bronze 1 got 8/2 and got plat V... like seriously can anyone explain if this is a bug on player behavior or, I am missing something with the system. I just feel as if it is unfair for players to be put in low positions due to a reason which isn't clearly given to us, I carried 6/7 of the wins (not as If that matters) but I just feel as if some people that were like "bronze 1" to "plat V" who I hate to say this thing but isn't at the same skill level as some people aka me. So can someone explain what has happened or what could have happened because otherwise it's just frustrating.