Why do most landing pages fail — is it design, speed, or messaging?

I’ve been diving deep into how founders launch their first products, and one thing stands out:

👉 Most landing pages don’t work.

• Some look good, but load slow.

• Some are fast, but the message doesn’t connect.

• Others nail the copy, but the design feels “off” and doesn’t build trust.

As someone building my own startup right now, I’ve been obsessed with this question:

What’s the single biggest reason landing pages fail to convert?

Personally, I think it’s less about features and more about feelings:

• Trust (does this brand feel credible?)

• Speed (do I feel respected as a visitor?)

• Clarity (do I instantly know if this is for me?)

I’m working on a React-first builder to make this process easier, but I don’t want to just solve it for myself — I want to hear from this community:

🔸 What’s the #1 thing that makes you bounce from a landing page instantly?

🔸 And if you’ve built landing pages, what was the hardest part to get right?

I’d love to learn from your experiences (and maybe spot some patterns together).