I guess I fail to see the difference between God destroying Sodom in the Old Testament for their wickedness, telling Abraham he would spare the city if he could

I guess I fail to see the difference between God destroying Sodom in the Old Testament for their wickedness, telling Abraham he would spare the city if he could find even ten righteous men in it, and then Jesus claiming to be God in the New Testament (John 8) and saying that soon, Capernaum will be judged and face a fate even worse than Sodom because Sodom was morally better than Capernaum.