ranked system

Can someone plz explain the new ranked system to me? I just played a ranked game where my team was had a 1 bronze, 3 silvers, and 1 gold versus 1 silver 3 golds, and 1 plat. I thought that you didnt get matched up with people that where in that far of an elo range like bronze n silver yeah or silver n gold yeah but to have a bronze n plat in the same game something is wrong. It makes climbing pointless n makes it to where ppl wont want to play the game anymore.