The Nether update to Minecraft in 2020 changed the Nether Realm completely and added the most desired ore in Minecraft, the Ancient Debris. The ancient debris is used to create netherite scraps that, when combined with four of the gold ingots will give you a Netherite Ingot.
The best netherite tools and armor are highly prized and most players aim to have a complete set. The best time to spawn ancient debris is at Y level 15. It can be found in all biomes and is equally distributed. However, there are biomes that provide a greater advantage and can improve the mining experience.
This biome is not the best for mining ancient debris because it contains blackstone and basalt, which can spawn underground quite often. These blocks are more difficult than the netherrack, and decrease the durability of your pickaxe's pickaxe quicker.
The biome also contains dangerous elements. These factors make it very difficult to mine in this biome.
Although this biome is made up netherracks it is not well-suited to mining Ancient Debris as it also spawns mobs like Piglins or Hoglins. Underground miners have the potential to run into hostile mobs that can hamper the mining process.
Hoglins are able to attack players and, if they're not treated properly, can even kill them.
Soul Sand Valley is a biome that looks desert-like and is covered in soul sand. This biome can also be home to Skeletons or Ghast, which can make it difficult to mine for ancient materials.
This was the original biome of the Nether Realm. It is made up of netherracks. Zombified Piglins are the only ones that it spawns. They do not attack players until they become aggravated. This biome is safer than other biomes and can be mined for ancient materials without fear of hostile mobs.
This biome is only home to the Endermans occasionally striders. Both of these mobs are non-hostile. Only Endermen will attack players if they are looking directly into their eyes.
This biome is ideal for hunting ancient debris because of the low number of hostile mobs that can spawn there and the netherrack blocks which can easily be mined.