Why not load all content at once but use infinite scrolling?

I'm creating an eCommerce website, and I've read numerous posts about making the UX better by loading more products when the user gets near to the end of the page. However, why not just load all products and use a script like lazyload to load images later? That way I think it would depend less on the client side, therefore making the browser more responsive.

So here is my main question:

Why not load all products at once and load images separately?