@olgha he's not an ambush class any more, he's literally a walk into you and you die unless you're a scout and you're far enough from him. but even then it's very annoying because of the fire particles. yes you CAN play around a pyro and counter him reasonably effectively at high level but it's very aids to do so, and slows the game down since you have to play a bit further away from chokes
unlocks such as the detonator and scorch shot dont have any real counterplay except playing faster rather than taking the slow fight, but there's times that isn't as viable