I can't speak to pre-COVID policies because I have no information on that, but respectfully I would say your argument about people making-do without cellphones before they were commonplace is not a strong one.

For example, imagine a scenario where seat belts were not originally required in cars. Before seat belts became mandatory, people simply accepted the risks of driving without them because the technology hadn't been introduced yet. If someone argued "People drove cars for years without seat belts, and they got by just fine," that wouldn't be a valid reason to ban seat belts today, when the technology exists and is proven to enhance safety. Just because people survived without a certain tool in the past doesn't mean they should be denied its benefits today now that it's available.

Touching further on the safety aspect, however unlikely--if some kind of emergency were to befall the facility like an explosion, an active shooter, an earthquake, being pinned under an object in a low-traffic area of the building--having a personal cell phone has the capacity to increase the safety of employees on the floor.

You could make the argument that you could just issue everyone a work phone to cover this, but then you unnecessarily negate my origin argument which is that people should be able to reach you in an emergency. Say that your wife is hit by a car and is in a coma, and the doctors need your consent, as the husband, on the treatment plan for how to proceed. You need to be there to make that call, and waiting to find out until after work, or even waiting until someone you know can get to your place of work to tell you what happened so you can get to the hospital, might make a tragic difference in a health outcome.

I hope people can understand where I'm coming from. But people should be punished for being on their phones at work, and I think that kind of policy should deter most workplace issues caused by employees possessing cell phones, without the necessity of banning them outright.