Computers have not superseded humans in mathematical research. That is way beyond anything that we can program into a computer. Computers are better at computation, which is not the same thing.
More generally, the fact that currently humans are the only entity observed doing X does not mean you need to understand humans to understand X.
If we do build AI, maybe we'll never know if it's conscious. You can't know whether any other human is conscious, either. But you can know whether they make you laugh, or cry, or learn, or love. The knowable things are good enough.
If we build AI we could only know if its conscious if we know what conscious is, and that is something we do not know, and perhaps will never know. It could be fundamentally beyond our comprehension.