We might be focusing on different parts of the DMG. The parts I focused on and remember well are the parts that have nothing to do with D&D. Take Chapter 4: Creating NPCs. The first half of it is about fleshing out memorable characters quickly, which is a skill useful for any tabletop game (or just general fiction writing). It advises you to flesh out occupation & history, appearance, abilities, talent, mannerism, interactions with others, useful knowledge, ideals, bonds, flaws and secrets, with sections of examples and tables for quick generation, as well as advice for what to focus on really quickly. Most of the rest of the chapter is the same for villains, with little D&D-specific bits filling the remainder.
Or the play style section in chapter 1, which is about how different people play for different reasons, and you should get to know whether which of your players are looking for hack and slash, versus immersive storytelling. That's even more important in other kinds of games than it is in D&D!
I haven't actually played D&D in a long time, but it's been very useful for me in other very different kinds of games, and even fiction writing. I'd recommend you take another look.