Giants are still in minecraft's code I think it would be cool as a rare chance for giants to spawn in minecraft as a boss mob. They would be a raid class mob such as pillagers and they could act as a raid leader with hoards of undead mobs attacking villages.
Why? I don’t see a purpose considering villagers are already almost defenceless. We don’t need another reason for me to spend my entire life in a village trying to keep them safe. As is, they are already dying because they only have iron golems that don’t even spend enough. This would absolutely destroy them even more.