This is Michael Pollan, professor at Harvard University & Knight Professor of Science & Environmental Journalism at the UC Berkeley Graduate School of Journalism. Impressive. Here he is talking to Joe Rogan, podcaster & professional gullible person. Professor Pollan is wrong.
People (who exactly?) were not drunk that much, they didn't drink alcoholic drinks all the time. They did drink a lot of beer/ale, but often with a very low alcohol percentage. It wasn't the only thing they drank either.
People didn't drink it because it was safer than water. They drank it because of it's taste and nutritious. And generally humans like a bit of change in their diet, they don't like not drinking the same stuff all the time.
Medieval people HAD clean water. Water came from wells & fountains, water was piped in from springs. Groundwater is pretty clean and there were strict laws related to making sure that the drinking water & even ground near wells and such didn't become polluted.
They also knew what dodgy water looked/smelled/tasted like, but yes, certain microbes/bacteria could not be spotted. They knew how to boil & filter water though... And guess what, to make ale or even beer, you need clean water to begin with.
Yes children also drank this very low alcohol percentage beer, no, they did not drink hard cider for breakfast... Making beer (not typically ale) also involves boiling... Europeans have had hot beverages before the 17th century...! Lots! For 1000s of years!
People have worked and still work nights without caffeine. I don't drink coffee... or alcohol... or do drugs... guess who regularly works through the night. Just because someone has impressive titles or has been on Joe Rogan's podcast doesn't make them right.
Sources & references:
https://www.medievalists.net/2014/07/people-drink-water-middle-ages/
http://www.jbsumner.com/blog/2011/08/small-beer-to-you-perhaps/
https://www.ianvisits.co.uk/blog/2017/01/02/the-myth-of-medieval-small-beer/
https://slate.com/human-interest/2013/05/medieval-europe-why-was-water-the-most-popular-drink.html
https://leslefts.blogspot.com/2013/11/the-great-medieval-water-myth.html
https://fakehistoryhunter.net/2019/09/10/medieval-myths-bingo/#nobodydrankwater
https://history.howstuffworks.com/medieval-people-drink-beer-water.htm
https://www.tastesofhistory.co.uk/post/dispelling-some-myths-dirty-water-drink-beer
https://medievalmeadandbeer.wordpress.com/mythbusting-medieval-brewing-preconceptions/