It looks neat, but unlike the Hans Rosling example someone else mentioned, the animation adds no additional information. Showing just the last frame would get the same point across much quicker and more accessible. It's a form of chartjunk.
On YouTube you can see how well this works. There are channels with a huge follower base just existing because of this animation.
But you're very right that this indeed relies on an emotional component to achieve the full effect of conveying time in two dimensions. If there's no emotional attachment to the outcome, our brains don't process the highs or lows. In that case, a variance chart like open/close prices on the stock market might work better.
A chart that works that way is the title equivalent of “you won’t guess who wins”.
I get sucked into those “X over 50 years videos” and watch to the end to get the satisfaction. But it doesn’t help me remember the outcome at all.
It’s just engagement bait in video form. A chart on a webpage like this is just chart junk like the poster said unless it’s actually updating in real time.
In the animated version, a human observer here is allowed (forced) to occupy mental states of a real-time observer. They have the experience of "X has jumped ahead - I wonder if it'll last - oh, wow, Y is really surging".
The visceral experience matters, and is impossible to recreate post-hoc if all of the info is presented up front.
(edit: "more information" in so far is it informs more - leaves more impressions on the observer)
2. The Chartjunk wiki cites Adolf Loos's idea "ornamentation is a crime". But I think we're done with modern minimalism and in the process of rediscovering the joy in ornamentation. This is an aesthetic choice and you may disagree.
No it removes information; to be able to focus on one period at a time as it evolves.
Seeing a "living graph" of how something evolves is different than seeing the graph fully drawn statically, that cannot be considered chart junk IMO.
Because the underlying assumption is that accessibility and the ability to grasp the data that is being conveyed isn't completely dependent on the audience. If I happen to prefer a static chart, an animated chart might still convey the intended thing in a stickier way, to a wider audience.
if i had a dashboard i needed to use at work set up like that i'd have a bloody conniption after a week. but this isn't a work dashboard -- it's a functionality demo and i'm more likely to remember echarts now as a result (purpose of examples achieved).