When it comes to learning new things... I believe gaining that information nowadays tends to often be via online resourcing-- websites, apps, video. So as the instruction of world-building is mainly towards newer players-- and those newer players tending to be of the younger generations-- teaching via book is not used or as necessary as it was for the Gen Xers and above. If the younger generations want to learn about more advanced Dungeon Mastering techniques (including building your own worlds)... I suspect that they will get that info online and not via any Dungeon Master's Guide. Thus, printing information in the new DMG that is pretty much the same repeated information that has been printed and had videos made about countless times before is probably not the best use of page count.
People nowadays are always making jokes about how no one reads the DMG... well, that's because they are all watching YouTube videos on how to learn to DM instead. Heh heh... what WotC should be having Chris Perkins or some other YouTuber do now is a series of YouTube videos where they narrates each chapter of the new DMG and talks about what is said in them and how to put them to use. Because while barely anyone will sit down to just read that book anymore... thousands upon thousands will watch videos of someone talking about it, LOL.
People nowadays are always making jokes about how no one reads the DMG... well, that's because they are all watching YouTube videos on how to learn to DM instead. Heh heh... what WotC should be having Chris Perkins or some other YouTuber do now is a series of YouTube videos where they narrates each chapter of the new DMG and talks about what is said in them and how to put them to use. Because while barely anyone will sit down to just read that book anymore... thousands upon thousands will watch videos of someone talking about it, LOL.