In a certain sense ‘Big Philosophy’ is dead: grand metaphysics that explains what the world really is behind the scenes, and how everything in it relates to everything else is afaik not practiced anymore at any serious university. Such metaphysical systems designed in the history of philosophy are still studied in philosophy, from purely historical interest on one side, but also because many of these systems contain ideas that can also be useful without taking into account the complete system.
I think there are several causes for this ‘downfall’: in the first place the development of science. It turns out that many questions that philosophers thought can be answered based on simple (non-instrumental) observation and reason alone, can be accessed with more advanced methods, and get much deeper results in this way. So the domain of philosophy became smaller. On the other side philosophy developed in itself: it discovered that the questions and answers on philosophical questions are highly dependent on the theoretical and cultural background of the philosophers. So philosophy became more and more a ‘critical method’: how to clean our intellectual glasses so we can get a more objective view. Kant started this movement with his ‘Critique of Pure Reason’, but he made his idea in a ‘Big Philosophy’ himself. But the idea was picked up and developed in different directions, very often with an emphasis on the dimensions of language: as analytic philosophy], as philosophy of communication (e.g. Habermas]), or as critique on language as instrument for intellectual and cultural imperialism (e.g. post-modernism]). As different as they are, they all are in some way, one more radical than the other, critiques on ‘Big Philosophy’. Post-Modernism even uses the concept (taken from Heidegger) of the ‘End of Philosophy’, where ‘end’ is used in both its meanings: as the opposite of ‘begin’, but also as ‘goal’: a critique on all ‘Big Stories’ (that for many post-modernists include science).
But this does not mean there is no place for philosophy anymore, only that its aims are not that high anymore as they once were. But any philosophy that analyses problems about brain, conciousness, mind and free will is still philosophy of mind, and therefore is is not dead at all. And I think that we thanks and despite our extreme language capabilities, can have a much better understanding of our world than a goldfish can. So even if it is ‘just a matter of degree’, I would say is is a matter of millions of degrees.