Suppose the world establishes a fresh new state in a new land for all the asylum seekers. Now they can live there peacefully, right?
Well, wrong. Who would be ruling them? There will be power struggle. And as like the conflict why they weren't able to live in their own land, they won't be able to live in this new land too.
Any nation that can rule themselves can live in their homeland too. If not then they will need foreigners to rule them.
BUT foreigners' rule is "occupation" and they will seek "independence". Leading to conflict, deteriorating situation and then seeking a newer land to start over, again. Rinse, repeat.