The human capacity for paying attention has been shrinking rapidly, furthered to a great extent by the great advances made in communication technology.
In cricket, Test matches running into 5 days were the craze. Then came the One-day matches. That transition took some time. But the next phase of T20 was quick and brutal. While those who love cricket genuinely and play the game know the worth of a Test match endurance and quality, most spectators would any day prefer a T20 game over a Test.
In the entertainment field there were long movies, screened only in theatres. That was the only place one could watch movies. Then came the television and other platforms where one could watch old movies from the comfort of one's living room. Then came sweeping the 'reels-era'. Now most people are addicted to scrolling reels on their mobile phones. Not just in one's own living room, but anywhere and everywhere and every given time! Movies lasted 2 to 3 hours. Now reels last not more than a minute.
For information, one had to read newspapers. Today printed newspapers are hardly subscribed for. There are ample apps which provide 'news bits'. Just a para or a couple of lines. That is sufficient. From leading lengthy news articles to news slightly longer than the headlines, information grasping has shortened.
The worse hit has been book-reading. Except, perhaps research scholars, and ardent book lovers, there are hardly any people who 'have the time' to read a book!
More than the decline in attention span, the speed at which that span is declining is alarming. Dopomine acceleration is indeed sabotaging the deepening of wisdom. Information is today the biggest risk to knowledge and wisdom.