When a level 30, who most likely sucks, duos with a level 5, the level 5 should be taken to level 30 games, not the 30 taken into level 10 games. It just becomes a brain-dead stomp, especially when that level 30 plays Lee Sin or Yasuo, clearly because they lack skill.
I'm watching a RL friend try and play the game. I actually feel bad for him versing a level 30 Yasuo toplane. So much so that he pretty much quit. Thankfully I was there and proceeded to dumpster the Yasuo, who in turn rage-quit for losing to a level 10.
If people wish to play with friends, make the lower level go up, not drag the 30 down and ruin new players trying to learn the game. The moment a smurf plays Yi, Lee, Yasuo, or Katarina, you know they're bronze.