The Lord would speak to Moses face to face, as one speaks to a friend. Then Moses would return to the camp, but his young aide Joshua son of Nun did not leave the tent. Exodus 33:11 (NIV)
“Its lonely at the top”
There are many reasons why this is a valid statement, be it issues of trust or otherwise. But for all the reasons for loneliness at the top, it’s more effective to take someone along.