I found a modded Minecraft SMP called Gilded Abyss and it just started Season 2 a couple days ago. The whole season is going for a medieval era vibe and it feels like a story server.
When you join you end up getting sorted into one of two groups. As the server goes on both groups get daily tasks and it sounds like it will push people to team up and actually do stuff.
There are lots of biomes to explore since it uses Biomes o Plenty and Terralith. There are also special items you can get in certain ways and you can pick an origin race in game to match your playstyle.
They also have custom bosses for harder fights and the Create mod so people can build machines as long as it is reasonable. The End is locked for the first week and then it opens with an event.
It is whitelisted and you join through a ticket system where you talk to the owner or a moderator first. They want player suggestions and they say there will be lots of events.
