This is such an outdated argument. The reality is that if the bottom line and quality of work being done, and possibly employees being available to contact during set work hours (although this is a two way street and if required then boundaries should be in place to protect employees from being disturbed during non work hours too.) is up to par, there is no reason to worry about something as trivial as time theft.

When I hear complaints like this, all I can picture is the stereotypical "Karen" middle manager who does all their work with their fists firmly planted on their hips now realizing how unimportant they really are.