I am always queued with the best players that know what to do in any situation , will always know what position you take and will totally headshot you if one pixel of your hitbox shows up on their screen. Why??? Can somebody explain?

So Ive already used my first unlock to get viper because Ive seen how good she is in the game and I'm loving it but I know nothing about the other agents and every tier list is different so I wanna get some recommendations for my second age...