There's a distinction between changing someone else's political views and inflaming their existing views via outrage, fake news, etc.

If one is easier than the other, then this article does indeed explain things. Cambridge Analytica may be unable to change political views, but it may have been capable of mobilizing a select group of disenfranchised voters that it carefully selected.

Given low voter turnouts, you can increase chances of your candidate winning by merely improving turnout for a select group.