Want to go back and look at something again? You now have to wait for the animation.
This is objectively bad design. I want static PNGs or SVGs, not JavaScript.
Also, that site got in my shitlist for taking control of my keyboard. I prefer to use the arrow keys to scroll one line at a time, and the stupid JavaScript on that site made that impossible.
Actually, I'd be happiest if that entire page was just a single static .svg file.
If you're going to present a graph, the point of that graph is to be understood so it needs to be read easily and promptly.
Animating the graph every time you move up or down the page gets in the way of that analysis. It erases the data you were about to look and forces you to wait needlessly for it to appear again.
Try to look at one graph and quickly go back to a previous one to check it out in comparison or anything. It's absolutely uncomfortable.