Tiny little pedantry I can't let go: when someone seemingly holds two incompatible beliefs at the same time, that is not "cognitive dissonance", per se.
It's lack of cognitive dissonance where it should be expected. Cognitive dissonance is exactly when you realize that you hold incompatible beliefs and thus begin to feel upset and attempt to resolve them.
Instead, the common use of "cognitive dissonance" to describe unexamined incompatible beliefs would be probably something more like "unjustified cognitive consonance".
But this is probably already a lost battle like "momentarily" meaning "in a moment" instead of "for a moment".
At the same time I think there's also a lot of "unjustified cognitive dissonance" caused by thinking two beliefs must be incompatible when they are not necessarily so.
For example, believing that "the Internet has done a lot of good" and "the Internet has done a lot of bad" at the same time is perfectly reasonable.