It used to be that wealthy people were the leisure class, and having time off was a status symbol. That's switched now: being busy and overworked is the reality for many white-collar workers, and there's a kind of perverse currency to that, competitive busy-ness. At the other end of the income scale, there's a swath of lower-wage workers who are underemployed or unemployed, with too much unwanted leisure, and zero status for that. For shift workers, devices mean they're accessible in ways they weren't before, susceptible to that call from the boss to log more hours.