Smurfs exist and they exist in all the ranks. It’s a problem because they ruin the experience for non-smurfs. If you assume yourself is not a smurf, then you will over time see more smurfs on the other team than on your own, so it does hurt your rank, but that takes a backseat to the awful gaming experience you have when you have to play someone who is clearly so much better than everyone else.
We aren’t talking about a DPS who might enjoy dueling a DPS a lot better than them. What we are talking about is trying to play support against a smurf Tracer that keeps wrecking y our backline over and over again.