The recipes are such a small amount of the secret knowledge now. There are so many quirks to the game to discover, even people playing 10+ years still find joy in discovering them (or being taught).

Community is a huge aspect, shared learning, collaboration, cooperation

Imagination also plays a big role. You have to create your own story and see things not as they are, but as what they are to the story. It's reminiscent of childhood and play. HermitCraft is the most notable example of this, but it's pervasive, especially among builders. (i.e. put a railroad on a smoker to make a grill, flower pot as a cup, extended piston as a table, or a fence post with a pressure plate as a table)