In addition to that cite, you have to remember. Why must you carry a log book, when you have electronic logs? Same reason. You have to be able to provide on demand and if your phone, ELD, or company is unreachable, you are most likely getting an OOS or having to wait until they can. I carried a Verizon Mobile Router with me, and had the company send what logs they had, before the glitch. I used my own notes duplicating log entries to fill in the missing parts. This was before ELD's became mandatory. The company was pushing into it, finding out who to use, doesn't matter, glitches are still happening and you're still required to have a current RODS on demand.
The real question is why are we using paper at all at this point? There is zero reason all BOL’s can’t be electronic provided your device has an internet connection.