It's possible you and your acquaintances can't tell. Similarly some people claim they can't tell a difference between a 720p video and higher. Or that they can't tell a difference between 128 kbps CBR MP3 and higher.
However the differences are real and have been measured. [1] [2] You are welcome to argue that the performance work isn't worth prioritizing, but don't fall into the trap of claiming the performance gap doesn't exist.
--