personally I agree, however you might need to look at your friends list first, to state the fact I am normally unranked I cant stand being ranked at all but this season I made s4 just like in season 4 anyway. the point is if you play with people who are a higher rank than you and they are in your friends list you will notice that you begin facing people of an increasingly higher level and rank, my example is after one match with a friend who happens to be plat 5, I began seeing gold to diamond on my team and the enemy team.
now I use lolsumo and if I view my matches when I win I normally place from gold to diamond on lol sumo, when I lose I place plat to bronze, the matches that have the lowest scores are the ones where I face people with mixed teams, because if you have too large of a skill gap between you and your teammates then you are just asking to lose because the higher skilled players will always expect more from the lower skilled ones because its what they are used to