Thanks for that point—I hadn't even noticed that the curse on Canaan is actually Noah talking.

And you're quite right that the Cross should have ended any curses, exposing the actual Evangelical disbelief in the Jesus event. They do not believe a messiah came!

My own view is that Caanan's curse is a narrative meant to suggest how the Nephilim (giants) continued after the Flood. The term 'cursed' is a biblical cue to the crime of the Watchers, as Michael Heiser notes.

But this requires some knowledge of the Enoch literature, etc., as Christians don't usually have.