Problem is not that BR and JH lack AC Passengers. The problem lies that barring few areas like PNBE-BXR,PNBE-GAYA,PNBE-KIUL,GAYA-DHN, DHN-ASN-DGR, JSME-ASN, TATA-KGP, road transport is always either faster or shorter or simply the rail connectivity isn't there.
Just see the railway connectivity woes that people belonging to South Bihar face! There is no proper train between GAYA-MFP, DBG and other areas in Mithila. Even Trains to Bhagalpur and Munger are so slow that road transport is much better option.
Jharkhand is an even more bizarre conundrum when it comes to it's railway...
more... network.
Say I have to go from Dhanbad to Deoghar or Giridih. By Road it takes 3 hours via the new DHN-SBG road. By railways on the other hand, the rail route is far far more and clumsier. Going to Giridih via Madhupur from DHN would be a cartoonish experience imo 😂.
Then you have the problems similar to what parts of Bihar experience.
Jamshedpur has negligible connectivity to the Palamau, Garhwa and Western Jharkhand. Dhanbad and Ranchi lack connectivity to areas like Chaibasa and the Kolhan region. Santhal Pargana is cut off and hugely dependent on Deoghar. Areas like Koderma, Ramgarh, Hazaribagh are much better connected by roads than by railways.
Also, the roads in Jharkhand have undergone great improvement particularly the roads connecting the three biggest cities Jamshedpur, Dhanbad and Ranchi.