A few years ago I heard someone say: “Every hour of sleep before midnight is worth two, and every hour of work before noon is worth two.”
That’s a pretty good principle in general. It would need to be nuanced, of course, when it comes to those who are naturally most productive late at night. But as a general statement, it points to the high productive value of making the most of the morning.
Although maybe you could have the best of both worlds. If you went to bed at 9 pm, you’d have six hours of sleep by midnight and could then get up, ready to attack the day…