Evidence shows that early exposure to potential allergies reduces the likelihood of getting that allergy. Since we've know this doctors have recommended early exposure to allergens, instead of avoiding them. Now that we no longer avoid peanuts before adolescence, the allergy is receding.

The article is paywalled but the gist is in the tagline: people kept peanuts but babies for fear of allergies but lack of exposure leads to allergies.

I've been casually following this for awhile so here's some further insight: peanut allergies were on the rise worldwide except in one place...Israel.

Have you ever seen those "puffs" baby snacks? They're like Cheeto Puffs but made for babies. Easier to eat with a weaker flavor. They're popular across the world but there's a brand with a peanut variety that sells particularly well in Israeli.

After realizing the connection, they started studying it. I am assuming this article is the conclusion of that study.

Non-evidence-based medical guidelines caused the spike as explained here.