Remathilis
Legend
Because a human DM can communicate with, respond to, and understand human players. A computer can't.* A human DM can say to the players, "How should we address this?" A computer can't. A human DM can show both spontaneity and foresight that are well beyond what a computer can do.
*Even the best LLMs and other "AIs" do not understand anything at all. They're just complicated matrix multiplications.
The bold is precisely why it cannot be used.
Nope. A sophisticated nonsapient AI could do clever things. But it could not be kind, enthusiastic, and heartfelt. Only a sapient AI could do those things, and it would be slavery to design such an AI. (Unless, of course, the AI is free to choose...at which point you can't be sure that it will be fair.)
However, if the DM is bound both by the rules and the dice, I fail to see a need. I don't need a DM to apologize to me while he's TPKing the party. I need a DM who can read a room and decide it's probably not in the best interests of the game to use the random encounter result he just rolled.