It is difficult to build/create something you don't understand. A computer is just a playback machine for binary logic. We know that "intelligence" can create binary logic. We don't know if binary logic can create "intelligence". Claims that it is possible are really more "religious" than scientific at this point.
What is "religious" is this inclination to treat human intelligence as this magical thing that works outside the laws of nature, as if our neurons and our brain were something other than just chemistry doing very complex things. That would be quite an extraordinary claim that requires equally extraordinary evidence.
What we do know at this point is that no amount of "just chemistry" has ever managed to create even the most rudimentary form of "life" from inert chemicals.
And the only working models we have for "intelligence" at this point are inextricably bound to life.