Creeper biome/structure

The piglins and endermen get whole dimensions. Mooshrooms, axolotles and mooshrooms get whole biomes. Guardians, illagers, and more have their own structures. But what does the creeper have? Nothing! I got this idea while thinking how after awhile, if you don't fix them, your world will be filled with creeper holes. But in a new world the is no evidence for them. You could have biome or structures filled with crators. Or plenty of other things. What are creepers doing when not blowing up players?