On topic: give me a 5E equivalent of Pathfinder's Complete Campaign, please: lots of DM facing rules for everything from domain management and mass combat, to environmental hazards, planar travel, etc... I don't expect a whole line of books a la 3.5 era guides, but one big DM expansion would be lovely.
Yeah, I think there's a whole grab bag of things that could be added. We have a little bit here and there like with Tasha's but I want a supplement that just focuses on world building.
Problem is the main target of that is DMs and they're only a tiny subset of players.