We don't mind information density, but most people find it easier to process less information.

The youtuber mentions that "Asians" can process information faster than "Americans"

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They said East Asians, my comment - given the other statements made in the video I would assume the ability to process more information is due to cultural training - you always process more information, get page with less information seems weird to you, need more information to feel secure that page is way it is supposed to be... thus the ability to process more information is a self-reinforcing cycle.

I think this changed mainly due to the rise of mobiles. Websites have to be readable on small screens (‘mobile first’).

I wonder how they do this in Japan.

Of the 3 times I was in Japan, many websites didn't work correctly on mobile or didn't work at all and required desktop.