This is a complicated story. The goal seems to be to get all of Jacob’s sons to Egypt.

In the Zohar, Egypt represents complete separation from God. It is the most advanced civilization on the planet. It’s pantheon of gods is highly developed. At the time of Joseph, unified Egypt has been around for two thousand years.

Why would anyone want to leave and go back to herding sheep in Canaan?

There is no God in this chapter that is visual. There is, however, the development of Joseph as a man and his instinct to get Benjamin to Egypt. Why Benjamin specifically other than that he wants to be reunited with all his brothers? Or maybe he only wants to be reunited with Benjamin. He does not ask about nor ask them to bring Jacob to Egypt.

The trip from Egypt to Canaan is probably a few weeks to a couple of months.