It's an idiotic premise. Turn up to work drunk and see how well you do.
Who the hell would want to do a labourer's job drunk.
Who would hire someone drunk?
Imagine the whole workforce drunk?
Even tipsy, seems worse, the afternoon sucks after lunch drinks.
I think if you look at current 3rd world countries they are not far off culturally to 'Early Modern People'
There's a huge crutch on alcohol, it kills a lot of people.
But most people are not drunk (or tipsy) most of the time.