Repetition
One of the building blocks of propaganda is repetition.
You can take a simple idea and just repeat it again and again using different media, from multiple information sources. Over time, the target audience stop questioning the validity of such idea and accept it as an axiom.
In a world of infinite feeds and ever shrinking content, you don't need a nuanced argument to convince a population, just keep repeating the same simplistic idea, again and again. Success is almost guaranteed in the end.
If you think you are smart enough to pinpoint the propaganda you have been fed since childhood, think twice.