Indeed it has long been known that the awake human brain operates near a critical point. Unfortunately, their significance statement is very generic and doesn't

Indeed it has long been known that the awake human brain operates near a critical point. Unfortunately, their significance statement is very generic and doesn't really summarise their main contributions. The abstract has more information, describing how this paper adds to the picture a mathematical determination of that critical point, and the insight that low-frequency oscillations play a key role when switching consciousness states. The level of the experiments is quite high, also they use primates (humans and macaques), some of them epileptic, and they administer psychedelics. All this sets the paper apart from lower-tier work. It doesn't strike me as a real ground-breaking paper, but still an important contribution to the field. And the methods are impressive.