Does anyone know the design choice/reasons for this? I completely understand every bullet after or moving while shooting being innacurate/less accurate but no matter how I spin it in my head, it seems strange.

This means every headshot you line up 15-20 meters away has a 1/20 chance of whiffing, potentially costing you your life that round/economy due to no fault of your own.

I understand that RPG games (Pokemon, FF, DQ) use crits to essentially create excitement but almost anti-crits feel out of place in a PvP competitive setting.

Side note: Does anyone know if this has ever cost someone a round/game in pro play?

Lastly, I'm sure this post probably has been made before so I apologise for that but I just discovered it in-game for myself so was curious what the consensus is on this and typing things like "riot first shot deviation" and variations didn't lead to much.

Edit: Oh and the numbers are guestimations. I don't have the exacts. I only just discovered this myself.