I have taken 3 round trips in the past month and noticed that my flight was delayed 5 out of 6 flights, the longest being 1 hour.

Also I noticed that when the incoming flight is arriving at 8.35pm (30 mins late) the departure time for the next flight will show 8.45pm which is not realistic to unload and reload a plane.

At that time, the pre boards only started going into the plane at 9.00pm and we took off at 9.20pm, 1 hour late. Is that a simple way to make us not so worried? Because in the end, our scheduled arrival time and actual was also 1 hour late, but the flight attendents made 3 announcements that passengers who had connecting flights have nothing to worry about?