I found a survival server called CaveMC that is semi anarchy and feels like enhanced vanilla. The whole overworld is underground so there is no surface at all. It uses custom world generation made by real Minecraft developers and the caves stretch forever with biomes resources and structures.
The vibe is brutal survival and you really have to be resourceful to make it. Season 2 is a fresh start with a bunch of additions.
There is also a Wasteland Dimension that opens on November 8th. It brings brand new gear to fight over plus huge mega structures with mysteries and valuable stuff. It also has its own unique currency so players can make a new economy and trade. There is a new spawn too and the dimension is a custom generated map with special features.
