Why is my MacBook screen so dim in direct sunlight?

Your MacBook screen is dim in direct sunlight for two reasons that stack. First, the glossy panel mirrors the sky back at you, so the deck reads as a gray smear. Second, on a MacBook Pro 14"/16", macOS caps everyday brightness at roughly 500 nits even though the panel can hit about 1,600. That's the limit macOS sets, not the limit of your display. An app like MacBrightness opens the brighter range Apple holds in reserve, on the same keys you already press. It's free to try with Splitscreen Mode, then $5 to keep. Direct overhead sun still beats any laptop, but in open shade or a bright balcony, it's readable again.