Placement matches in lol

Just wanted to say that last season i peaked at gold 2 whilst finishing up at gold 4. So i play my placement matches this season winning 8 out of 10 of them and it places me in silver 5. imo i feel that these matches have little to no relevance what so ever. It's seems to me that riot aka rito pre determines which league you're going to be placed in b4 you even play your matches.