Not only personal time, but work time as well. How many of us see work colleagues on their phones or random websites during work time? If that moment of boredom had been spent thinking about new products, the details of a customer problem, or something else work-related, that could have produced something tangible, rather than being wasted. When "slack time" is automatically used for indulging in phone apps or web surfing, that's displacing activity which pre-phone-apps and pre-internet, would be much more likely to have involved alternative productive activity, from future planning to work-related talk with co-workers, to designing and prototyping experimental stuff. Now it's self-indulgent skinner boxes compelling us to fairly fruitless time wasting.

Some people are so focussed on this stuff that it takes priority over actual face to face conversations, which I personally find intensely rude, and I don't think I'm wrong in saying this is going to directly affect the productivity and effectiveness of them as an individual and the team as a whole. Their focus isn't on the company's business, but on themselves. I don't find this degree of self-absorption healthy; it's like working with zombies. In some ways, I preferred my original programming job where we only had a shelf full of books and dial-up internet, and you actually worked with your co-workers, talked to your customers on the phone, rather than merely existing in the same space while their minds are somewhere else. Not that I'm a Luddite, it's the social changes I abhor, not the technical.

It's weird, and worrying, just how addicted people have become at the expense of real life in the here and now, and a pushback against it is long overdue.