I prefer to explore and complete quests that aren't part of a big story because it feels like you are more limited if you are following a story. If this was added I hope there will be a option to turn it off.
I love this, you have put a very powerful question in my mind😅
We can have quests like raiding orc camps or ranger towers, basically quest related to structures rather than just NPCs. And the main objective can be to open chests or replacing banners and can also be journey related