I think there is a hugely greater percentage of pilots flying fatigued than flying under the influence of Alcohol.
Most Airlines now roster max FDP followed by Min Rest ad infinitum.
Don't forget there is a comparison chart of Hours Awake/ Alcohol Equivalent.
Filed under, as has been for years, 'an inconvenient truth.' As a result nothing will change. If there is not a solution acceptable to share holders then the problem will stay 'undiscovered'. This is not the only such issue in commercial aviation. Standards and quality are under threat the whole time and dribbling downwards. If they can get away with it, they will. Until there is a problem, there is no problem. Yet we are in an industry that supposedly prides itself on anticipation of problems and being proactive. IMHO that has disappeared long ago and we've been lucky so far; or perhaps not considering the number of serviceable a/c that have come to grief for bizarre human factor reasons.