Legend says that a long time ago there was a champion 
who used to counter the marksman class. He was stuck down by a mighty force known as Riot. There is a small smigen of hope that he will return but nobody has seen him since season 4.
Elkington3 votesI don't like how people use the term "stat checking" for the simpler melee champions they don't like, while marksmen are generally the ranged overlords of stat checking.
Ashe, Quinn, and Teemo are the only ones that somewhat deviate from this, regardless of their current strength. The former has a wealth of utility, while the latter two have absurd map control.
All of the others just turn into generic auto-attacking death-dealers, that kill everyone if they're not killed fast enough. They offer nothing to a team outside of damage, so it basically comes down to which one does the highest damage the most reliably. I feel the game would be in a much better state if Riot didn't balance the game around these kind of marksmen.
Chembaron Yamada1 votesThere are more marksman providing utility and other stuff for their team, though.
These have some good utility for their team
Sieging potential and being able to block paths against flanks
Engage with ult and vision utility with W
Critmaster Garen3 voteswe need this back to do its job. 
feeding time2 votesStop complaining about ADC. Yeah, they're strong. They also have counters.
These include, but are not limited to 
Dead flag blues3 votesStop complaining about ADC. Yeah, they're strong. They also have counters.
These include, but are not limited to
GA / Death dance / Hexdrinker fuck them hardly. Let's not forget that they usually have a support that stick to their ass and can nullify any assassin (hello Lulu's polymorph or Janna R/Q/E). I agree that lethality is too strong atm, but adcs are supposed to be squishy and require placement, atm they can just stand still and right click (Varus says hello)
Chembaron Yamada2 votesWhat exactly do you mean by counters. For example: in a duel, divers and assassins will win most fights against a marksman.
Moonfall Saber1 votesbut they wont in the real game
xGunna12 votesyasuo is good unless if skillful vayne player
Spicy Rice2 votesNah, yasuo is hot garbage atm. He has a 44% winrate