For a moment, vapes were as stylish of an accessory as a Telfar bag. It was hard to walk downtown without getting caught in a cloud of blueberry vapor. Now the conversation around vaping has shifted from begrudging acceptance to vocal disgust. Lina Edwards, a 26-year-old who works at a med spa in Ohio, remembers the first time she heard someone refer to a vape as an “adult pacifier.” The thought of sucking on a Watermelon Ice Elf Bar for comfort was embarrassing enough that she eventually quit. It added to the humiliation that her best friend often showed her men’s Hinge profiles that included responses like “Deal-breaker: you vape” or “No astrology, no vaping.” She’s not the only one who’s tired of sucking on a piece of plastic. After a decade of steady growth, e-cigarette sales have tumbled; in the U.S., they’ve fallen nearly every month over the past two years. Hitting the vape is now déclassé, a habit associated with teenagers and men who live in their parents’ basement. But whi...