I forgot to add the description and chapters. I added them now.

They go over how the web and frameworks decided against horizontal, apart from deliberate emphasis, they go over some desktop layout attempts, failures and successes (more of the same vs navigation), a chapter about (paper) documents as the source, and endless panes now using horizontal.

the web is not vertical because the spec demands it, the web is vertical because the people who design websites the people who write the frameworks and the people who teach usability all agreed implicitly and over 20 years that sideways was a layout failure

It's also how we're trained for thousands of hours to read text. Left to right, then progress top to bottom. That makes more intuitive sense to more people than scrolling endlessly to the right.

This would be my guess. Fingers can wiggle up and down easier than side to side. /shrug

Tldw? (Any video is Tldw)

Mousewheel. End of study.

I watched this yesterday, I can heartily recommend it. I then went down the rabbit hole learning about Dynamicland.