AI got it from people though.

I too am saddened by the instant-polish marketing pages everyone and their grandma deploys to Render, but also some people at some point in time really did make these effects. And they are nice. HTML based UIs will always have a place in my heart.

Btw: actually I think webflow did more to pump this stuff out to the masses. The animate on scroll being the biggest offender. It's so good, but not for every literal text paragraph on your local bakery's website.