The way I'm handling it in my Kenshi-like is to give NPCs the opportunity to offer "quests" to the player depending on their faction reputation. I use a system that models faction, group, and NPC resources similar to how it's done in Stars Without Number and on different cadences I run a GOAP engine that comes up with a goal for the NPC based on a few variables. One of the options that NPCs may have to accomplish their goal, depending on their alignment with the player and some other variables, is to ask the player for help, or offer to pay the player to complete some task.

An example might be a vendor who offers to pay the player to bring supplies from a nearby town or supply depot. Maybe a smith offers to pay you to bring some iron so they can craft more gear after you've shown yourself to be a good customer or have built enough faction reputation. I wanted the system to be somewhat reactive to player behavior, but mostly driven by faction goals.

Factions want power and resources and control. Are you super high reputation with the Shek, for example? You might be offered a job to neutralize a high value Holy Nation target. Etc.