SWG for example had all items being player-made in addition to slowly loosing durability and breaking eventually. That means, instead of finding loot you can then use indefinitely, you were dependent on economy supply chains. SWG also made you dependent on player services - like doctors, entertainers and such.
I think there could easily be many casual friendly playstyles, like farming, harvesting, herding, entertaining, being mayor in a player city, etc. - in addition to more combat oriented play. Players should be able to choose one style or the other, or mix and match to their liking. And every such playstyle should both need and provide "stuff" from/to other playstyles on a regular basis.
It is a very strange "game" though, so I understand why it's not for everyone.
One obstacle you have to overcome is that there has to be an investment that is risked by the players. There's not much of a cost to gank someone usually, or it's simply not allowed at all except in a controlled way. One thing that forces people into social cooperation is to protect against the potential for loss. As I understand it, confrontations with other players in EVE Online are dangerous because of that investment of time and/or money. That's part of what makes roguelikes and battle royales so compelling. That said, you have to balance it against being appealing enough to more casual players--how do you encourage investment without making it a boring grind or too expensive?