When my dear late husband was little, he found he had a severe peanut/nut allergy. At the time he was the only one in school who had it. ( he was 90 when he passed, so it was a long time ago.)
My daughter, who is now 60, also has the allergy and in school she was the only one she knew of who had it.
Both husband and daughter learned to live with it
But now?? So common!! Would love to know specific reasons why.
Also wonder if it is from soy based formula given to babies. Soybeans and peanuts have some of the same allergens.
Or maybe it is because of baby food. Kids used to eat what mom and dad ate just mashed a little. They also used to be put on solid food as fast as possible. Nursing was physically demanding and put a major drain on the mother. So while they might continue to nurse they also supplemented with solid food keep the baby fuller longer.
Then again it might be something else altogether.
Something like the A1/A2 milk.
People who have trouble with A1 milk (from Holstein cows) can drink A2 milk (from jersey cows) with no trouble.
Perhaps they bred something out or into the peanut that either used to prevent the problem or now causes the problem.
There are so many variables. And they change from person to person.
I suspect it's the pesticides being used on the peanuts, not the peanuts themselves.