whats the point of ranked teams?

so solo players can play with friends (EG a plat, a bronze, and a gold can all play together without ruining individual MMR)

it allows people to play more competitively with a team, you don't need to look for scrimms with other real teams, because many 5 man ques are soloque players who thought they did well together one game so they have no synergy and others are friends who aren't taking the game seriously