HR training definitely worked well for me when I was a newbie. The whole reason I was building up my running fitness was in order to run a marathon as comfortably as possible after 9 months from scratch, so I found perhaps the biggest benefit was the reassurance of an objective measure of effort, in telling me that I wasn't going too fast, either from an intuitive point of view of being able to keep the pace going for increasingly longer long runs, or more specifically because I was avoiding burning too many calories in the form of carbs rather than fat, so avoiding "the wall" when the long run got really long.
TL;DR - HR training isn't the only way of doing things but it's a bloody good one if (a) you're trying to build an aerobic base and/or (b) you're relatively new to structured training and you're delving into the unknown w.r.t. run length/volume of training.
HR training definitely worked well for me when I was a newbie. The whole reason I was building up my running fitness was in order to run a marathon as comfortably as possible after 9 months from scratch, so I found perhaps the biggest benefit was the reassurance of an objective measure of effort, in telling me that I wasn't going too fast, either from an intuitive point of view of being able to keep the pace going for increasingly longer long runs, or more specifically because I was avoiding burning too many calories in the form of carbs rather than fat, so avoiding "the wall" when the long run got really long.
TL;DR - HR training isn't the only way of doing things but it's a bloody good one if (a) you're trying to build an aerobic base and/or (b) you're relatively new to structured training and you're delving into the unknown w.r.t. run length/volume of training.