>>16436846It's cultural, and also the streaming landscape is different in Japan.
In Japan, the big streaming platforms are Youtube, NND and Twitch, in that order I'm pretty sure. Mildom gets some use, but I don't think it's higher than Twitch.
In NA, it's Twitch, Youtube, Facebook. Yes, facebook, if I'm not misremembering some of the numbers.
The audience on Youtube for Primetime NA is simply not the same as it is for JP, and the specifics of how things came to be would be more of a history lesson that I don't think I'm qualified to write about since I don't know enough about NND.
Point is, stream-watching on YT is much stronger in Japan than it is in NA due to market forces as much as cultural ones.