Whom do you hold in higher regard: Jimmy Carter and Barack Obama, politicians known for often working from early morning until late at night; or Keir Starmer, the new U.K. Prime Minister, who declared he wouldn’t work past 6 p.m. on Fridays, and Ursula von der Leyen, President of the European Commission, who took a few weeks off after her re-election in June? The answer is an obvious one in America. Busyness and a lack of leisure time have become pervasive status symbols in the U.S. that most...