How expansion packs used to be. The last game I saw get a DLC that basically added twice as much game to the game was Shadow of the Erdtree and before that, was probably sometime back in the early 2000s before Oblivion released the Horse Armor.
Obviously a very different kind of game but the Factorio Space Age DLC more than doubled my play time in the game and imo is one of the best DLC value-wise that I’ve ever purchased.