Why are landing pages so incredibly uninformative? In practice, I spend under two minutes to click around and see if can 'get' it. What does it do especially

Why are landing pages so incredibly uninformative? In practice, I spend under two minutes to click around and see if can 'get' it. What does it do especially well? What's the syntax look like? If you are brave, what doesn't work well? No idea why this exists or why I would use it. Bad website. No cookie.