Heads up! Some biomes datapacks might not be compatible with eachother! If you go into the datapack's minecraft folder, then go to dimension, at least in mine there's an overworld file. This basically tells the game to replace the normal biomes with this set (and the set usually has all the default biomes in it). If you go in and see my custom trench biome for instance in Decay and Devine, you can copy and paste that piece of code into another datapacks overworld file that may have other entries.

If a pack does not have that file, then it uses a different method I'm not familiar with in adding biomes, and of course 1.18/1.19 packs might not vibe well.

Hope I made sense!