There were many surprises in Avengers: Infinity War, most of them deeply depressing. But one of the more unexpected was the way in which the Russo Brothers turned Thanos from the two dimensional purple baddie he'd been in the MCU to that point into a genuinely complex and interesting character. Their stated aim for the movie was to make him the centre of it; even though he's the villain he goes on a warped version of the hero's journey. Plus, his Malthusian philosophy kinda makes sense if you skate over the murdering billions of innocent people part.