Never did I mentioned that they don't undergo route maintenance/inspection but don't remain idle for unusual long hours at depot past inspection/maintenance!!
Maintenance isn't limited only to Rake but track/station are kept to adhere norms/protocol while on-board facilities don't compromise basic Hygiene!!
We had filthy 2/3 class & delayed train in British Era which straightway is followed by IR where low class travelers eventually pay for high class traveler's luxury!!