I have been thinking about this in the context of Gang PCs. I am not sure if this would be appropriate for other factions.
My idea is that each Gang seems to have a set number of "permanent" NPCs on the Grid. There could be a process created whereby a character can meet a certain list of requirements, and then "challenge" the NPC to take their spot. The challenge would be having to beat the NPC in combat.
The primary benefit I see to this is variety. The PC's "final gear" would become the NPC's default gear. As they lose it, they would ask other characters to find replacement pieces.
The sense I have is that the ganger combat dynamics are pretty well known. Gang A fights with Weapon X. Gang B fights with Weapon Y. etc. Having "new" NPCs with different weapons and fighting styles would freshen up that dynamic.
Maybe the character also has a preferred drug or drug combo. That could carry over to the NPC as well. Again, that creates a more dynamic environment and also provides work for characters to source that / those drug(s).
Another benefit I see is that it might encourage people who otherwise wouldn't play a ganger, to play one. Depending on the requirements, it might encourage ganger characters to stay around longer. For example, if the character needs to reach a certain "rank", or be with the gang for a certain length of time (minimum of 12 months or whatever).
As a long term dynamic, NPCs who lose could occasionally (once a year or whatever) challenge their way back. Staff could have the NPCs fight each other. Kind of a survival of the fittest, strongest rise to the top thing. If the challenging NPC loses, they aren't allowed to challenge again until every other retired NPC has had a shot. This could be turned into an annual event. Each gang (or faction) holds a challenge once a year. Gangers might do it publicly, or semi-publicly. Other factions might do it in secret, or only extend invites to certain established characters.