When I apply eyeshadow for eye makeup, the color doesn't show up well. What should I use as a base?

You know how when YouTubers apply eyeshadow, the color payoff goes "Ta-da!" and looks great?

But even when I apply eyeshadow, it goes on faintly, so I don't think it's a problem with the product.

Because I bought a product that a YouTuber uses....

So I keep applying layers and layers, and it ends up getting really dark. What could be the problem?

I tried applying eye primer and even tried applying a light shade of eyeshadow, but the color payoff isn't very good.

On YouTube, the color comes out beautifully with just two or three brushstrokes, so I'm sad~