My best idea so far for addressing this is to give all players exactly three characters, which they can switch between at any point. The goal would be for most of your "boring" productive output to be determined more by (character) resource allocation rather than participating in the grind yourself all the time.

For example, a group of players might establish a small town with its own laws. The benefits of joining this group would include protection of your self and your stuff from bandits, access to resources, and potentially a place to train in your character's skills. You might in return be required to allocate a certain amount of your characters' combined time to boring scriptable work like tending crops or patrolling the borders of the town.

You would have to design the game so that most players would feel naturally inclined to join some kind of group, whether to avoid being picked off by other players in the wilderness, advance their characters, trade, or just to have something to do.

It might not be made super-obvious to other players which characters are linked to the same player, but I think there would have to be a way to discover it in-game, or too many players would end up as double-agents. Maybe some ritual to discover a player's "soul bonds", and if they don't consent to it when applying to join your township then you would probably treat them as super-suspicious. :)