I think a bit part of it is that it's simply become harder to live with ADHD and for it to stay under the radar in your life. Rare is the person who can survive in the modern world purely on their wits. It demands that you persevere at jobs, careers and relationships over long timespans, and against an onslaught of things which have been relentlessly developed and refined over generations with the express purpose of hijacking your dopamine system and interfering with your free will.