Dairy milk is not nutritionally necessary in any age cohort. If you enjoy it, that's fine of course, but it isn't required if you don't.
https://www.mayoclinic.org/diseases-conditions/lactose-intol...
It's fine to research and make decisions about your diet which are in line with your own understanding, philosophy, and dietary requirements. Please don't pretend that your views on this are particularly useful for others.
Increase might be a better word than improve. Number of "diagnosed" cases might have gone up, but I'd argue accuracy of diagnosis has gotten much much worse.
There was a recent study showing only about 1 in 10 people who claimed to be allergic to antibiotics actually had any allergic or other negative response to them.
https://www.pharmaceutical-journal.com/learning/learning-art...?
Also, there's a fairly foolproof test for lactose intolerance.
Almost no infants are lactose intolerant, for obvious evolutionary reasons (mother's milk is full of lactose).
(Ref: 'Little Britain') https://youtu.be/FmD2Y6WxpIw?t=61