Here is a list of Things that would make party members good.
Party being able to LVL up and gain xp.
Player being able to have 100+ party members but only an X amount being active and being able to swap Inactive ones and active ones making the player create their own Party.
Having an option to remove the player from battles making it so you need the party for combat.
These changes would make it possible to make more types of games like Monster tamers and improve existing Genres.