Air India Delhi - Kochi flight takes off after 12 hours: Why was it delayed?

An Air India flight from Delhi to Kochi, which the flyers booked paying an exorbitant amount during the festival season, was delayed for almost 12 hours without even offering passengers a reason. The flight, which was supposed to depart at 8.55 pm on Friday, finally took off at 9.30 am. The delay affected the holiday plans of Malayalis heading home for the Onam weekend.
Like many earlier instances, the airline did not arrange food or other facilities for the passengers who were stuck at the airport, which led to many protests. The airline has not provided any official explanation for the delay yet, though it's speculated that technical issues are to blame. 

Meanwhile, a handful of passengers have also been complaining about other delayed flights of Air India around the same date. A flyer shared that a flight from London to Kochi was cancelled on September 6 after many delays, leaving over 200 passengers stranded. Apparently, no Air India staff assisted them either. Apparently, the airline hasn't provided any explanation on this either. Air India has replied to his comment on X, assuring him to look into the matter.