You're right that audience data is going to be full of the obvious. But it's also good for watching trends, before they go bust. A number of genres (e.g. superheroes) have cycles of growing, being massively popular, then dying off for a couple decades.

If you're in the business of making content, you want to join the trend early and get out before everyone realizes it's a fad. A truly great movie can buck trends, or even change them, but there are few truly great movies. Or you could just ignore this all and make the perennial favorites, generic romance or action movies.