We will never replicate the real thing closely enough. Microbiome/proteome alone is going to be impossible, without all the small peptides and antibodies - it will never be the same.
Milk itself isn't the healthiest food either. Cow milk is the most prevalent allergen, but it's mostly chronic inflammation instead of full blown anaphylaxis and thus ignored. You do not have to be lactose intolerant, it is true allergy to proteins in milk.
https://www.arthritis.org/health-wellness/healthy-living/nut...
Humans were not supposed to eat it. It was just something that helped us survive in frozen wastelands.