Do that many people really have work phones that are mobile devices? I've had a desk phone at several jobs, which I pretty much never use, but I was only issued a mobile device as work phone once. I never really used it either. Yet people talk about this as though it is a common thing. Is there some specific industry or type of job that routinely gives people mobile devices for work use?
It's more that tech people are willing to use company chat outside of work. At a minimum slack is very handy for "I'll be late in today" from the train, and I don't mind using my personal phone for that.
