I think that there were a lot of random rolling tables added to 5e as a way to court OSR's love of random tables.
But I really think that the One D&D DMG would greatly benefit from looking at the structure and layout of the 4e DMG:
1. How to be a DM
2. Running the Game
3. Combat Encounters
4. Building Encounters
5. Noncombat Encounters
6. Adventures
7. Rewards
8. Campaigns
9. The World
10. The DM's Toolkit
11. Fallcrest
Not pictured is how each chapter begins with bullet points that provide an overview of the chapter contents. Notice how the book starts from the basics of being a DM and builds up from there to running various types of encounters. Then it goes onto Adventures. Then Campaigns. Then the World. It starts narrow in scope but then it widens its scope. Then finally at the end is a DM Toolkit as well as a sample starting location (i.e., Fallcrest of the Nenir Vale). This format, IMHO, made DMing far more approachable for me.
I played in 3e, and I only really played in 3e because I did not find the 3e DMG to be all that accessible. 4e changed that for me, and one reason it did so was because of how its format, spacing, layout, and structure presented the contents.