last time (~ half year ago) they thaught me this they said chest compression is more than enough. there should be enough oxygen in the lungs and blood till professional help arrives, and as you said most of the time airway is blocked in these situations
also most people are extremely unconfortable to blow air through someones nose/mouth, so it incrreases the number of people that are willing to help
at least sa far as i know
is cheaters in lol this bad? are there more cheaters compared to for ex.: dota? and if yes, why? does the lol game implementation allow it?