where a 30ms difference in reaction time is noticeable (this is less than 1 frame in a fighting game, for example)
You have some pretty bad understanding of how netcode works if you think a 30ms ping in an online multi-player game means your game or input is delayed by 30ms. It's a lot more complicated than that, and especially in games with bad netcode you will absolutely notice a difference between 10ms or 30ms ping