I drink coffee every morning and have for pretty much my entire adult life. People might be better off for it because coffee in moderation is healthy and has various bioactive compounds in addition to caffeine that can reduce risk of some diseases... but I don't think the caffeine itself has any cognitive benefits for me at all compared to if I were to never drink coffee. It's just an addiction I'm completely adapted to, and skipping a morning coffee just means I'm a bit extra tired and sluggish through the day. Maybe dopaminergic stimulants are different, especially for people with true ADHD, and they can maintain an effect over time even at a dosage plateau.