The problem with claiming that consciousness is just a complicated computation is not merely that we simply haven't advanced our study enough to understand it. The problem is that what we know so far about the nature of computation seems to directly contradict and falsify the notion that consciousness is just computation. To put it simply: our knowledge of computational complexity, algorithms, and general problem solving shows that our human intelligence performs far more sophisticated operations than are possible given the number of neurons that exist in our brains (unless there are some super-fast algorithms that we haven't discovered yet, which would have massive implications on the P=NP problem, and our understanding of physics).
Related video about why we don't have AI yet: https://www.youtube.com/watch?v=c3of7xYoMQM