Why is it a myth that muscle turns into fat when someone stops working out?.

I read multiple sources. Most of them sited this.

Muscles are developed in response to stress in the form of resistance training. It is true that once this stimulus is removed, the muscles sense they are no longer needed and the body breaks them down, but fat is not their fate!

the muscle can't turn in to fat, I mean eventually the muscle is super weak but it doesn't turn to fat.

hey, the answer to your question would be a.) progressive resistance training.