Read the following passage and answer the item that follows. Your answer to this item should be based on the passage only.

A screen is now within arm's reach at nearly every idle moment, and the habit of filling every such moment with it has quietly replaced the discipline of sitting with an unstructured hour and deciding, unprompted, what to do with it. Where earlier generations might have had to invent their own entertainment, or simply endure boredom until an idea arrived, today's default is to reach for a feed engineered to be more immediately absorbing than any idea a bored mind might otherwise produce. The result is not that people today are less capable of deep thought, but that fewer of them are practising the specific, unglamorous skill of tolerating boredom long enough for a genuinely original thought to surface.

According to the passage, why do fewer original thoughts surface today?