Verses in question:
Genesis 11:5: “The LORD came down to see the city and the tower which the sons of men had built.”
God chooses to go down and investigate the Tower of Babel because the people are building a tower so they can reach up to Heaven. This tower is so unimpressive though that God is said to “look down” so that he can see it, thus it is nowhere near the glory of God. The point is that the text is emphasizing, and belittling this challenge against God by saying that he “came down to see the city and the tower.” Does God need to do come down to Earth to see what is happening? No.
Secondly, the text is also deliberately putting emphasis on God’s interest in what is happening below. To “look down” or to come down shows God is interested in what is happening on Earth, especially something (as the building of Babel) that is challenging his authority.