Let's not make such hilarious sweeping assumptions which carry a huge error margin. Your keyboard latency for example is slightly less then one order of magnitude off. Even more so for PS/2, which is IRQ based port, but regardless...
I have even better one for you. One of the most if not the most competitive game in the world, League of Legends has had a brilliant example of just how little small mechanical changes in game dynamics actually do. They had a champion who was considered massively underpowered. They posted a patch that apparently buffed him. Suddenly pro circles picked the champion and used him actively with great degree of success. This lasted for a while.
Then suddenly came the apology from Riot, the company behind the game. They forgot to actually push the changes into the patch.
Vast majority of competitive scene "little tweaks matter" is same as various variants of snake oil for top athletes. They allow people who are already in extreme shape for their discipline to get the extra "push" from thinking they have an advantage. It's literally all in the head of the recipient. A pure example of placebo effect. Because when you spend a little time actually thinking about it, you'll realize that round trip "signal received in optical nerve, signal transferred into brain, signal processed into thought which produces desire for action, signal is sent to brain area responsible for pressing keys, signal encoded into actual signal that causes finger action, signal is transferred into appropriate muscles, muscles contract causing pressing action" simply takes so long, that a difference of a few milliseconds is simply IRRELEVANT. It is far less then difference between taking that same long neural signal trip on two different occasions. I.e. error margin.
But reality is, placebo works. As long as you're convinced that you have uber keyboard, you'll likely perform better. Just like athletes who apply snake oil to their bodies before performance will perform better if they believe that snake oil gives them the edge. And the hardware companies want to sell you the expensive snake oil. Win:win.
Only one problem - it doesn't work on people who don't believe in that variety of snake oil.