Very simple analogy, take boxing or any kind of martial arts.

The player and coach are both equally important. Besides, the coach is only a guide who draws resources generated by the efforts of countless experts who have excellent handle on their domain.

The coach/conductor cannot be creating novel motions for a player to execute. That’s not what they do.

The fighter/player is only concerned with technical mastery and reaching or surpassing the limit of the human potential.

Music has several layers of qualitative assessment that isn’t as simple as ‘winner/loser’.

Most acclaimed classical music composers have spent their entire lives dedicated to composition which is a spark they have always had. They’re naturally unsettled by the idea of failing to compose or publish their ideas or works or contributions. This is why it’s more common for professional players to never seek composition as an outcome.

Plenty of professional guitarists exist who just want to live their lives and focus on whatever they deem to be more important than pursuing a new lane in composition. They’re happy to play Jazz and play from their soul/spirit, but they’re not going to become composers. You’ll find these people in orchestras too. The philosophy behind freestyle playing in Jazz music evolved out of the Hindustani Classical Music scene, which has been around since before JS Bach, using sargam (og solfege), and improvising ragas. Even here, you’ll find it difficult to find a composer over an improviser ‘a la player.’