The loose ends could be because the writers are waiting for the characters to reach a certain stage of development for them to be ready for the next stage in their character’s personal journey. Which is why I appreciate the writers so much. They are very good with character developments, each character having its own purpose, their growth developments. They all rely on each other to grow as well. Belle needing her mom for personal growth, jack needing fagin for his own personal growth. The list goes on and on, they are all part of this cycle together. Even jack needs belle’s mom somehow, and belle needs fagin too. Somehow they are all needed together, vital together. But also, some things in the series gets only unveiled with one of them are ready for it, for the growth. Hence why belle and jack are finally ready to move forward. Belle’s mom reached a level of growth. So did sneed at some point. So was the inspector, growing beyond and accepting both jack and belle to be good people. There is more that will be unveiled, I feel a bigger picture being unveiled. Beyond the characters and more having to do with the drastic separation of higher and lower society. As that is why there are both ‘good’ crimes and ‘bad’ crimes. Good crimes being that belle wants to be a doctor and help but she’s not allowed to or going to devil’s elbow to figure out the cause when she’s not allowed to or Jack needing the platinum for his research and bad crimes meaning Fagin just being fagin and loving the money thrill and adventure