I see this every so often but what is this?Domain management.
I think a lot of these are stymied by a combination of 5e having so many individual pieces designed to obliviate them so you'd need to tweak f/ex ranger "no I ignore that", outlander "no I find food for everyone", goodberry "I feed everyone for the entire day plus a bunch more with a first level slot", long/short rest mechanics that amount to "~givehealth 100<enter>" & so on. Others are made more difficult with 5e not including any magic item budget & assuming feats won't be used when designing things because there's no overhead left to provide mechanical benefits other than pure "here's a gold star" fluff from doing those things in a game. Put the two together & the system will fight you trying to create overhead in addition to trying to add the thing itself.Warfare/Mass Combat
Stronghold construction and management
Environmental rules, including for planar adventures
Robust economy guidelines so treasure has a purpose
Expanded travel rules including "journey" style mechanics
Downtime rules that actually work
Campaign creation and management tools
Relics, rituals, and general expanded magic options.
Like that.
I'd like to see variant tactical combat & rest mechanics written in a way that doesn't read like they were written by someone who dislikes tactical combat & the idea of attrition being a real risk to be concerned about. Some rules to expand the magic item budget that don't force me to be both the bad guy making PCs weaker as well as the author when I say "we are using these variant rules" would help too. Both of those together would help a lot with much of your list