Spot on, Intruder. In my day, most of the stuff was done on the radio due to lack of ACARS fit (even more distracting!) and often 'late'.
The system can work well, can achieve the 'Holy Grail' of 'on-time push' for the company BUT does require an Ops/Load Control that is on the ball and a flight crew prepared for the occasional delays in 'ready' so as not to delay others.