A GM's First Priority Is...

This is not so much a hot take as a tepid opinon.

What is a GM's first priority?

To entertain the players?

No, they have to work just as hard as the GM for this to happen. The modern vogue of GMs as free entertainers rankles me, and leads to games fizzling out.

To know the rules perfectly, and memorize the rulebook?

Again, I dislike the GM as computer school of thought, which leads to clueless players, one person stuck as forever GM, and GM burnout.

To adjudicate the rules fairly?

This is essential, but I would not call it a first priority.

To create compelling adventures?

Again, this is natural but not a first priority. Weak storytellers can rely on published adventures, stronger ones will naturally

What is the answer, then?

If you ask me, a GM's first priority is to lessen his or her workload. This will prevent burnout, but more importantly, let them enjoy the game, and be fresh enough to improvise when PCs go 'off script' during an adventure. It will also let GMing look like the thrill it should be when done right, and hopefully lead to players taking turns in the driver's seat.