I'm not assuming anything about what's possible.

I take issue with your assumption that there is some 'clear' distinction between the goal of '"building a simulation of the physical brain hardware" and the 'goal to simulate human consciousness". A distinction, if any, between those goals is anything but clear.

Further, the people most interested in 'physical simulation' also tend to be 'materialists' who think a suitably precise simulation can reproduce everything interesting about a human mind, including 'consciousness'. Without any personal 'leap of faith' as to whether that's true or false, this is an interesting and deeply murky question.