> If you believe the brain exists in the physical universe, that means you can build a physical system that also solves the same problems.
Sure, but in the case of computation, is it possible to make a computing system that has subjective experiences? Maybe consciousness isn't something that can be expressed in computational terms, because computation is itself based on abstraction.
I think that is extremely austere, and misses a large part of the value of science and philosophy. In some ways the questions of cosmology matter far less to the vast majority of humans, and have in practical terms less qualification and quantification for those people than subjective experience communicated by drama, poetry and art. Stating that this is meaningless ignores the suffering and joy of humanity, and makes an unwarrented and low utility judgement about the set of beliefs that are legitimate in finding how things are.