I was writing cover letters, double-checking my British spelling so that no one thinks I’m too foreign to work here, and I confirmed with my American friend Chris:
Me: Organization is spelled with an “S” over here, right?
Chris: Yeah, I don’t know why they bother with ZED. Like why even have it if you’re never going to uze it?
Amen. However, it is used occasionally to say “zebra” (“zee-bra”) as “zeb-rah”.