Your lands arent all Wastes, though
These spells are typically aimed at achieving a goal, functioning much like Mind Control by leveraging opponents' resources to gain an advantage in the game
Malamar's Psychic Recharge could charge Ultra Necrozma with Psychic Energy, Ultra Space searched your deck for Ultra Beasts, and Beast Ring could add more energy to your Pokmon, and Mysterious Treasure put Psychic Energy in your discard for Malamar to use while being another way to search your deck for needed Pokmon
This cares about Commander and multiplayer, but not formats like Type Four, Highlander, or Five Color or Pauper, just Commander specifically and multiplayer generally
The ability to reduce Character costs and remove threats gave Black a unique disruptive identity that punished greedy decks