It sounds like you got placed higher than you deserved, Dreddo. That can happen in placements because the deviation from each match is so high.
Of course I dont pretend I should be that high but there were joke games with ridiculous scores for …gold level (not placement).
I then started playing with my brother who had also similar experience (dropped to silver 2 and now is gold 2 again) and not only the games were close and competitive but also made an 11 win streak. I dont know if it matters but a lot of bad games took place early morning CET hours (I am European).