Personally, I interpret GP as we have already proven many of the true hypotheses that can be simply and easily formulated, based on the categories and concepts that we currently find intuitive.

And this shouldn't really be a surprise. Our cultures and societies have had thousands of years of evolution; our human instincts have had at least hundreds of thousands of years. In that time, both culture and instinct have picked up many true facts about the world that have helped us survive. A lot of science has been taking those facts and systematically investigating how far they hold.

So these both can be true: the more questions we ask, the more questions we have to answer, but also that many of the 'easy' hypotheses have been mined out, and any true advance in science will by necessity pull us further and further from the realm where our basic instincts and intuitions can usefully guide us.

Quantum mechanics being the prototypical example, of course.