1. Rebalancing. Buried Treasures, Shipwrecks... The loot was far too great for the point of the game you can find these structures.
2. Immersion. Extra Obsidian in Ruined Portals to help you rebuild what's broken, Kelp and Seagrass in Ocean Ruins, Torches and food in Villages. Changes like these are made to most chest loot tables in Lootery.
3. Incentive. Rarer structures now have far greater loot to make up for their scarceness. Uncommon structures like Woodland Mansions, Pillager Outposts and Jungle Temples loot has been massively buffed to promote finding them.
4. Ease. The primary change in this category is increasing the odds of finding Smithing Templates in chests. For example, Silence Smithing Template now has a 10% chance to generate in chests instead of a measly 1.2%, while Trims found in rarer structures have a 100% chance to be found there.

Entities

• Ghasts drop more Ghast Tears, up to 4 at once, because Ghasts are far too rare to only drop 1.
• Blazes have a chance to drop additional Blaze Powder or Glowstone Dust.
• Shulkers may drop both of their Shulker Shells, instead of one of them mysteriously vanishing.
• Drowneds may drop Prismarine Shards.
• Husks may drop Sand.
• Withers drop a lot of extra Coal, Soul Sand and Soul Soil.
• Piglins may drop Gold Nuggets and Gold Ingots at the same odds as Zombified Piglins.
• Wandering Traders drop 2 - 6 Emeralds on death.
• Villagers and Zombie Villagers sometimes drop Sticks, Wheat Seeds or rarely Emeralds on death.

Other

• Tamed Cats are more likely to bring Phantom Membranes in the morning.
• Sniffers have a 50% chance to dig up extra seeds.
• Piglins have slightly expanded selection of items for bartering. (they can now also give Ribs and Netherite Upgrade Smithing Templates)