RepurposedStructures VS Wynntils

Looks like either Additional Structures or Repurposed Structures

For now, I use Nullscape for generation, Repurposed Structures to add more structures, and Basic End Ores to make mining in The End worthwhile.

Repurposed Structures (Forge) (by telepathicgrunt)

I'm pretty sure they spawn in unloaded chunks. Also, if you want more structures I'd suggest using Repurposed Structures, Bygone Nether, and The Graveyard. Also, to make it easier to find these structures you can use Explorer's Compass. If you want to add more mobs I'd suggest Dragon Mounts and Lava Monsters. Also, if you don't want to lose your items when you die you should use either GraveStone or Corpse.

Forge: https://www.curseforge.com/minecraft/mc-mods/repurposed-structures

I don't have mods for everything you have asked for, but you can check some of the ones I know (1.18.2 since Terralith isn't 1.19 yet, I am unsure if it will be but I think it will) Terralith is a mod that adds very unqiue biomes without adding any new blocks to the game, there are some very interesting forests, deserts and even volcanoes Repurposed-Structures is a mod that adds new dungeons and other structures which as far as I know adds 0 blocks as well Better Village is a mod that makes villagers a lot more interesting in my opinion, I have never used it but it looks amazing from the images. Ambient Sounds adds a variety of sounds to the game and it make it feel a lot more alive Alternatively, you can use Dynamic Surroundings if you are playing 1.16.5, I like that mod a lot more

And finally, something like Repurposed Structures that adds more variants of vanilla structures to the game.

wynntils good basic mod pack for everything

nope, download it from their github - its the file under "assests" if you are list