This version of the datapack works with MC 1.21+ only
If you need this datapack for MC 1.20.x and lower, download it from here:
Let's loot some chests with hadron v1.4

Screenshots showing the possible contents of each chest are included in this zip file: screenshots. But if you like surprises, don't look there :)

If you've been playing Minecraft long enough, you've surely noticed that the game is evolving, there are new items, blocks and the content of chests, especially those that have been in the game "forever", remains the same. I'm talking about chests in villages, abandoned mines, strongholds or Nether fortresses, etc. Other chests also need to be refreshed.

I've seen a lot of Datapaks that change the contents of chests. I'm not saying this one is better or worse than the others. it's just mine.
I tried to use logic when deciding what should go in the chests. I tried to choose them so that they were things that are valuable in a given phase of the game. After all, what is "treasure" and what is "trash" for us changes as the game develops. When we start and in the first days we find a village or an abandoned mineshaft, almost everything we find in the chests is a treasure for us. Bread, torch, apple, stone tools are of great value to us. Not to mention iron ingots or iron tools.
But once the game has developed and we decide we are ready to go for example to the End, the situation is completely different. No one goes to the End "naked" (apart from speedrunners :D ) We want to take with us some reasonably good armor, sword, bow, maybe some potions. To collect it, we need time and resources. Surely we already have some farms in our world, including an iron farm. Therefore, when we defeat the dragon and go to the End Cities, iron ingots or blocks and iron armor found there, things that we would have died for in the first days of the game, are now worthless to us. Tell me, which of us brings iron from the End?
That's why I removed such things from the chests in the End. And other things that I think ended up there inexplicably. Well, tell me, what is the relationship between beetroot seeds and the End? Where did they come from? What would these beetroots grow on? On endstone?
Or how come saddles and horse armor in the End?
You won't find them there in my datapack anymore. I moved them to the Overworld, to the chests in the villages, where their presence is more logical. In return, in the End you will find (apart from the already known diamond, enchanted tools and pieces of armor) things closely related to the End: Shulker Shells, Dragon's Breath, End Crystals, Elytra or Fireworks Rocket, in case you run out :)

As for the chests in the Nether, the changes are that I removed the "junk". You don't risk your life fighting brutal piglins to find strings or iron nuggets in a chest. Now in the chests of fortresses and bastions you will find only what is worth taking home with you. Great explorers like Columbus or Magellan did not go to the ocean for a few months or years in their flimsy boats to get grass seeds or strings, but for real treasures.

In general, the loot is closely related to the place where it is located and its value depends on how easy it is to get to the chest and what stage of the game we are in. The more difficulties you have to overcome to get to the chest, the richer the loot.
Sometimes it's very rare and attractive things like elytra, the totem of undying. Or impossible to get like budding amethyst, although the chance of getting it in Ancient city is low.
I won't reveal the rest, see for yourself :)
Of course, I don't have to remind you that the changes will only apply to those chests that will be generated after installing the datapack.

I encourage you to check out other datapacks that I have published:

Let's loot some chests with hadron v1.5
Diamond geode v1.1
Real hero of the village v1.7
Amethyst beacon 1v4
Copper beacons 1v6
Skeleton skull from the nether 1v3
Magma cream from slimes v1.4
A little easier spire armor trim template and piglin's head 1v1