He did not ignore sin: he paid for it.
He paid for our sin, which cannot be ignored, it was placed on Jesus Who absorbed the wrath of God in our place.
In Exodus 34:4-7 God proclaims his character to Moses. He declares that He is merciful, gracious, slow to anger, abounding in steadfast love and faithfulness, forgiving, steadfast, and He will not put up with sin. God is holy and just, but He gives us ample time to repent and experience his mercy.
Exodus 34:28 we see that God alone is enough for us. It makes me think of this song by Meredith Andrews, “Christ is Enough for Me” https://youtu.be/Su1R5Ya2-P0