It's a chaotic format, full of unbelievable combos and political discussions at the table, and it's often an hours-long endeavor that never quite plays out the same
However, if one of them happens to die, you get a free creature
Stonespeaker Crystal is a reason to play a four mana rock that isnt Thran Dynamo or Nyx Lotus
This means that the slower pace of casual EDH and decks that can grind out longer games in cEDH can likely benefit from activating it turn over turn and amassing a ton of cards
One might argue that if you're going to run Kiki-Jiki in the 99, you might as well just make him the commander, load up on your combo pieces and have a winning deck
Tale of Momo Tale of Momo is one of my exceptions in that it only searches for allies, but it does search the graveyard and has a potential cost reduction