I have my phone in a very strong case, and it also has a neck/hand strap secured to it.
When the phone is in my shirt pocket, the strap is around my neck. If I happen to bend over really low and the phone slips out w/o me noticing it, it won't get very far. Not even as far as the floor/ground. It will be dangling from my neck.
If using the phone in a precarious situation, the strap is wrapped around my wrist... again, if the phone is dropped, it won't get very far before I catch it.
A bit of sensible precautions will take care of our expensive phones. I for one simply cannot afford to loose it, not because of the data and access to my private banking stuff, but simply because I can't afford to replace it.
I have never totally lost a phone. I have managed to loose one out of a shirt pocket years ago before they put tie loops on them.... fell into a puddle of water while I was cleaning my air conditioner outside unit (compressor and fins). You use a water hose to spray the fins to clear dust and spider webs.