+1 Not just intuitive! That is pretty much contemporary advice too. Although for many babies... cows, goat, or milk-like baby formula mixes seem to work out OK when the human-milk isn't available. And... I don't know of anyone or any study (I mean... WHO would fund such a study anyway) that has pinned down an exact age as when a person should quit milk.... completely.

As I've aged (in my 60's) I've lost some of my tolerance to milk and milk products. I've been told that is pretty much normal. But I still pour skim milk on my cereal and sprinkle a little shredded cheese on my salad. And so on.

If you've never shared a meal or a beer with anyone that owns and milks the cows.
If you've never helped plow, till, plant or hoe the fields where your vegetables are grown.
If you've never climbed the ladders and picked the fruit.... or spent time at the mill where grains are ground into flour.....
Then you probably should have concerns about the cleanliness and purity of your food supply. It would be only natural. But if you've lived around the food supply you likely have confidence in it.

Humans have feared the purity of the food supply.... since people first found themselves removed from it. Reading scary material written by others who... have also removed themselves from the food supply... doesn't help anyone.