In today's climate it's just not feasible to have LAN be the only true measure of skill, latency shouldn't matter as much as it does in a standard fps.
Aim down scope/barrel helps a little bit but not enough.
The FPS genre would need to be revamped in the direction of controlling sluggish mechs or something if it was to reach competitive success, or *brr* move entirely to consoles. Sticks enable less latency dependent online play.
The core of a successful ESPORT title is a large userbase, not gonna happen even if we'd see a 'Quake 5' or 'CS 2.0'.