Placements and MMR Clarity

I just don't get it. Why is there no clarity when it comes to ranking and MMR and where you're getting placed? I went 7-3 in my placements, ended last season Gold 4 and got placed in Silver 3. The previous season, I ended the season Gold 5, went 4-6 in placements, and got placed in Silver 1. I just don't understand how this even remotely makes sense. The lack of clarity within the ranked system is incredibly frustrating when you don't feel you are being rewarded for playing well/winning. I want to know why I was placed in Silver 3. What should I have done differently? What made me get placed lower than the previous season, despite ending a higher rank and winning more placement matches? #frustrated