Here are some and all things that I, and many, many other people would LOVE in PoC.
1. Villages. This would make it easier to obtain loot.
2. Villagers. These NPCs are dumb, but good to trade with. Mobs still attack them, which is why at night they run to beds, which brings me to my next suggestion.
3. Beds in survival multiplayer and private maps. This allows people to sleep at night.
4. Pillages and Pillager towers. This would be another challenge to the game.
5. A nether. This would be a fun new dimension to explore.
6. In the nether, new nether mobs. Ghasts, Zombie Pigmen, Piglens, hoglins, zoglins, Withers, Wither Skeletons, striders, blazes, magma cubes.
7. In the nether, new structure. Nether Fortress. This massive fortress in yet again, something to explore.
8. In the nether, new structure, Bastion. This building, over run with piglins, is a great place for trading and gold.
9. End. This would be an amazing new dimension to explore.
10. In the end, New structure. End city. This is where you can beat the enderdragon and the game.
11. In the end, New mob, enderdragon. This would be Poc's first boss.
12. In the end, new vegetation. Chorus plant. This would be a new source of food.
13 In the end, new mob. Shulker. This mobs spits an effect at you, levitation
14. To get to the end, new structure. Stronghold. This has many rooms including the portal room.
15. New structure. Desert temple. This building will hold loot as well as be a good base for some people.
16. New structure. Ocean monument. This middle-of-the-ocean building would hold a new boss, the elder guardian.
17. New structure. Tribal chambers.
18. New mob. Breeze.
19. New Structure. Ancient city. This new city holds the new boss, the Warden.
20. Deep dark.
21. Lush caves.
22. New mob. Axolotl
23 New block, piston. This blocks expands from 1 block to 2 blocks and can push blocks.
24 New block. Sticky piston. This block can expand and squish back, as well as push and pull any block.
I know its all a lot but i have confidence you can do it all. Btw this took me an hour to type. Be sure to check out my clan update post