through farming we have learned to acquire milk by fencing animals and forcing them to be milked and get knocked up. farming has only existed a fraction of how long humans have existed on earth though
so a wild animal that is pregnant running around you wouldn't be able to go up to it and milk it without getting a swift kick.
if you can tolerate dairy that is fine, but there is no way you can argue that another species milk that is zapped via a pasteurization process is in any way a part of a natural diet.
now I do eat some european cheese, non pasteurized. it is a treat for me maybe a couple times a month and has some health benefits like pro biotics so i am not 100% anti-dairy. but i am very adament that most people who reduce dairy and even quit it entirely will have tremendous improvements to their health by doing that. for one dairy is inflammatory which is not good