It’s not meant to be spoken, it’s supposed to be a writing standard as opposed to a spoken one.
“E” is also pretty common and it seems to be used interchangeably with “X”. That’s probably more of a personal choice.
“X” is also commonly marketed as “Yankee solution finding”, when it was first proposed by a Puerto Rican Psychologist to challenge the gender binary of Spanish. It is not an American invention, it just gained popularity there first.

