Coop issues in story mode

When playing lost ark in co op you can play in the open world but there times in the story when being bosses to mobs you end up getting separated . It doesn’t make sense why in co op why that we have to separate to do the same mission or fight the same boss. We should be able to do this together . If you are worried about it’s to over powering to the bosses then put warning up saying playing co op will raise the health and attack on bosses and enemies