So what is the problem with matchmaking??

Why is it that 90% of the games i play my team either has 2 gold people and the rest are silver bronze and we go against plat and gold enemies. To top that off our teams gold players are completely feeders. Or more often my team is all silver with a unranked or bronze and the enemy has golds and plats with silver. If this is caused by the group playing matchmaking thing maybe it would be better to make groups matchmake with with highest mmr players mmr. Its really not fun that almost every game i play there is 2-3 people on the other team that goes 20/4. Clearly outplaying everyone on my team.