Wasn't it in Drangleic that they found a cure to undeath? Or was it retconned in the Ringed City?
Considering the absolute wreck the world of Dark Souls was left in when we last saw it, those crowns are either buried under mountains full of ash, or their owner has long since skedaddled to go do whatever one does in a world that is literally grinding itself into dust. And I don’t feel like getting my shovel to go and find them.