Recognition

I saw in your interview with Reuven Seidler that you said that there is no good answer to Yom’s question about the fact that we have no way of knowing that our cognition is valid for the world and that we need to answer that we do have an intuition that is valid for the world. What about Descartes’ answer (I didn’t see him in person so maybe that’s not what he said but in any case I’m talking about the claim itself and it doesn’t really matter who said it): I think therefore I exist, I exist therefore God exists (we won’t go into all the proof now), if God exists then the way I perceive reality is the correct form because God is good and wouldn’t deceive me like that.
This is an answer that is built from a logical process and not derived from any premise. Why is this not a good argument?