Teemo annoys other toplaners. Yasuo annoys the whole other team.
When Teemo uses his basic abilities effectively, the most annoying mechanical interaction is TF or Udyr losing a stun on a 4 second cooldown (lower than the blind that caused the miss).
Post 6 the only counterplay is to have like a million control wards in your inventory at all times.
...Or simply activate Oracle's Alteration, and then get 10 seconds of going wherever you please while being immune to his traps and revealing them for everyone to attack. If your team has 2-3 of these, you can move with close to impunity. I spectated a challenger level game where AP Teemo got really fed, so the enemy team had five Oracle's Alteration, and it absolutely stomped him.
When Yasuo uses his Wind Wall effectively, the most annoying mechanical interaction can cause a significant number of the ranged champs in the game to entirely fizzle their ultimates, often simultaneously. Losing a 120 second cooldown to a Wind Wall is really frustrating. Very rewarding for Yasuo, but very frustrating for the other side. It has a lot of quality-of-life frustration effects too, like blocking Mikael's Crucible and Talisman of Ascension.