So, then what would a proper Sunday look like? God constructed us to require downtime for our mental well being. For some, that can take the form of sitting motionless on a couch all day. But for others, sitting still and doing nothing would actually be work. They would hate it. For them, rest takes the form of doing something they enjoy. I don't know why this would be a problem for God, or why He couldn't understand the truth of the phenomena.
This is a fair question. My fair answer is: I don't know. I only know what the Bible says: absolute rest. Devoted to God probably means that we should spend the whole day in prayer, adoring and worshiping God.
You say some people would be bored. Again, this is not about us but about God. We seem to think giving Him 6% is plenty. What do you think?
You know, Protestants/Baptists tell us that God created the world for His own glory and not for man. Yet somehow everyone thinks Sunday, the Lord's Day, is more about us and our needs than about God.
Come to think of it, we have made the same charade out of Nativity (Christmas).