You can even see it in social media, you can make out the common tropes shaped by the society/culture/subculture/mainstream media and while original thoughts and non-us/them|black/white comments are there, they get downvoted. Which is pretty sad. All the while, everyone thinks they're right and better than everyone else.
Japan's entertainment is not that different imo, most of it uses the same tropes, maybe with a small difference (that they later forget about). But yeah, some actually original content shows up more often.
That's not really true, it's usually the most popular as it's a money issue. Pick randomly a few seasonals and you'll find that most of them are not that good.
Otherwise unknown artists can and often do make a name for themselves by telling a good story, and their story gets boosted by a functioning entertainment industry.
Contrast that to America's entertainment industry. A filthy and incestuous cabal of people decide what does and doesn't make it. Ideological zealotry required to step foot at the gates. Serial rapists as the gatekeepers using their power to take advantage of others.
It's a huge problem. I have watched very little American media produced in the last decade because of this. Whenever some coworker talks about how great this new show is, I'll watch it and cringe. It's 90% an A-plot B-plot following the same tired template. Then 10% of it is doing some form of virtue signaling, grievance agitation or other propaganda technique to rile the plebs. I can only imagine people who watch it are desperate for any sort of escape from reality.
Outside the US, at least other countries play with different storytelling techniques. France with their 85 plots in a single story and Korea with their strong single plot driven by the main character's emotion. Plus, thankfully Japan's entertainment industry is going strong by having the different mangas compete with each other until the most interesting stories get adapted into an anime.