True AI will require several breakthroughs. The fact that we don't understand neural nets means that much of the progress thus far has been hand-wavy and hacky

True AI will require several breakthroughs. The fact that we don't understand neural nets means that much of the progress thus far has been hand-wavy and hacky iterative improvement (engineering, vs. theory). This means progress is very likely to plateau. When everything is hacky and you don't understand what's going on, those breakthroughs are not going to happen.