All of these techniques are a means to an end. That end is repeatability/predictability.
Most AG brewers, myself included, took a while before we knew exactly where our beer will "land".
Hitting things like mash temps, mash efficiency, boil starting and ending volume, etc, all tend to be somewhat wild at first. Getting them to a small std. deviation is a sign that you have control over your process. Making beer stops being a crap shoot and turns into a game of how accurate you can brew to target.
At that point, you'll be able to brew any recipe and deliberately nail it or at worst come really close.
And that's when you can then move on to dreaming up your own recipes and brewing and hitting them on demand, which IMO is where the fun really begins. I LOVE dreaming up a beer, designing a recipe to hit that profile, and then brewing a beer that tastes, looks, smells, and feels exactly like how I imagined it would.
HTH-