The problem is that most movies focus on either violence or comedy (stupidity), but rarely both. The future is both. I recently read the book "Drug War Zone" about the drug war in Juarez (near me), and the book is full of violence and stupidity of comic proportions. The only movie that comes to mind that combines these well is Fargo. Idiocracy may not be exactly accurate, but it deserves credit for popularizing the fact that the future will be stupid.
And its relevance to this forum is that the best/smartest guys tend to be the ones who have the hardest time attracting women. Unfortunately, this aspect of devolution wasn't covered in the movie.
Of course the granddaddy of brutality was quite a recent movie. I don't see this in the future in any form as it is so extreme even compared to favelas, but nonetheless, a very good movie well worth a watch: