I agree this type of web design sucks. It's been common for more than a decade - I remember Apple getting criticized for using this on the product page for the old "trash can" Mac Pro in 2013, and it was already widely used back then.

However, it seems pretty clear to me they did this in service of a joke - you have to "crank" your scroll wheel to get to the content, just like you have to crank this device. I think it's funny...