Riot needs to rework/fix their mmr system

So recently I have noticed that Riot's mmr system is really unbalanced. I am high Gold (with high gold mmr according to op.gg) and I have been getting normal games with mid to low level 20s. I don't know about you, but someone who is almost Plat should not be getting placed in games with some one who is lower ranked. It is absurd that I am getting placed with non-ranked players at all. A couple months back I was almost always being placed with low Gold-Plat players. This system is quite unbalanced for most people under high Plat elo.