Hatton vs. Witter springs to mind. Any others you can think of? Not fantasy fights but genuine fights from the same era that could have taken place but didn't due to several factors, such as politics, rival promotions, belts, weight etc.
Lewis v Bowe is an obvious choice Calzaghe v Froch but I understand Joe's reasoning. Khan v Brook, no way are we counting that corpse v corpse fight. Fury v Price. Let's all be honest here, Fury ducked the plumber.
Khan v Brook would have probably happened 2 years earlier if it weren't for covid so they would have been 33. You still think that's too late?