People drank alcohol if they could because it was one of the only liquids that was “clean.”
Everyone drank ale for the reason you mention. They used to process the ingredients three times giving three different strength beers for different people. The first and strongest batch went to the men, the second to women and the final, called small beer, was for the kids.
I once saw a record of the rations given to various members of Henry VIII’s court. A lady in waiting was given 2 loaves, a pound of roast beef and a gallon of ale for BREAKFAST! They must have been merry times.