Propaganda is a percentage game.
If you can silence the people in the public eye with a mic and camera in front of their face and have them repeat the official line, it doesn’t matter what a few non public dissenters believe.
Most people will go along with the official line because they don’t bother to find out what the truth is.
They will accept the “truth” someone they trust tells them is the truth because that someone they trust tells them they have done the work for them and this is the truth.
To this day millions of people believe the FBI files Craig Livingston got were used to blackmail republicans during Bill Clinton’s impeachment because Rush told them so.
Total BS, but they still believe it.