Buses serve different set of travelers and not end to end travellers. Passenger A travels from Esplanade or salt lake to Asansol or Durgapur but get down 5-10km before city centre. These passengers will save travel time in city and also money on local transport. Ease of my through apps anytime, seat selection are added features. Booking through IRCTC is a Hercules task enter captachas, OTP.