Lots of people are ranked lower than they should be... I placed in Proving Grounds the very first day, which is a brand new playlist of course, so there is no history or much of a ranked player-base to play against and factor into placements... did well, only placed Gold 3 or 4, I believe... I've been an Onyx ranked player since launch and I've been destroying in that playlist since it's come out.
A buddy of mine, who is highest-skill Diamond, placed Platinum a couple of days later, and I was out-performing him in his placement matches (not knocking him)... but by the time he played, there was more of a player-base that was ranked and a range of skill to play against and that affected the final placement. It's all when you place sometimes.
Then you have smurfs, and all sorts of other weird scenarios. Players under-ranked and stuck because they're held back by sub-par teammates... weird matching... Idk, the ranking system just isn't that great. Lots of room for improvement... Idk why they just don't start everyone out at Bronze 1 and just let people climb the ladder like H2 and H3. Lots of people have been pretty vocal about wanting a system like 1-50 for a long time now. It led to much more balanced and consistent MM, more often... lots of (+/-) 50-30 roundabout games in H5... H2 and H3 always had matches ending at 50-40, 50-45, 50-48... had lots more close, intense matches back in the day seems like... Now you have a couple players trying to carry the rest of their team on their back like 50% of the time. Then you see at the end of the game how skewed the ranks/matching was.
I'm not convinced that this is the way to go with ranks, moving forward...