Jason Jeong was a Cornell sophomore when, in 2016, he noticed classmates surreptitiously sucking on devices hidden in their sleeves during lectures. Jeong wasn’t the only one seduced by Juul, which combined the addictive pull of nicotine and the design of sleek tech products. By Jeong’s senior year, 2018, Juul Labs, the device’s maker, reached a $10 billion valuation, faster …
