How much fairer and frictionlessier do they become for every picosecond? Is there a limit to fairness and frictionlessyness?

Arguing about HFT feels like you're questioning people about why they're spending billions on excavating single, individual sand grains and the defense you get is "well, sand is an incredibly important building material. It is used in concrete, and we wouldn't have modern society without it". Sure that's true, but why is it that nobody can tell me how what you're doing is actually necessary for that.

Also, from a control engineering point of view, a lot more unstable.

With market "liquidity" that evaporates in milliseconds exactly when it's needed most...