[niemandhier]

I always assumed that it was more a case of behavior selection:

Yes, people did drink water frequently, but those societies and groups that regularly consumed fermented drinks like wine or beer, had on average a lower chance of consuming polluted water.

As a result behavior that favored drinking slightly alcoholic drinks became more widespread by selection.

This doesn’t require that people actually knew their water sources were polluted.

[wat10000]

This is basically the argument for respecting and following traditions even if nobody can explain why they're done.

[clickety_clack]

I’ve become a lot more circumspect about pushing through Chesterton fences as I’ve gained more experience in life.

I used to believe that we could determine a basis for most decisions from first principles. However, that requires a level of complete a priori knowledge that’s simply unattainable except for extremely niche situations.