Zack missed out on being either the hero or a main character in FF7 by like a week. The tragedy of Aerith and Zack is that they were good people cut down in their prime, and easily could have been the heroes of the game. You're like living in an alternate more tragic timeline.

Wild that Zack did not even exist in the original drafts, and Aerith's past boyfriend is just never touched upon. It also changes the context of Aerith-Cloud, as now you can see she's jus simping for a Zack copy.