iserith
Magic Wordsmith
If that was the case the unconscious condition would not say attack rolls against the creature have advantage, but instead that it hit autimatically like for Strenght and Dexterity saving throws.
Personally, I think that aspect of the unconscious condition is stupid. But in any case, the giant isn't making an attack roll against the unconscious character. It is just picking up said character. Grapple rules wouldn't apply in my view because the target is offering no resistance. Even if the rest of the grappling rules were applied, I certainly don't think there is any contest.