Lots of people "debate" the relative virtues and aspects of Japanese versus American styles of animation and comics.
A lot of people are going to take some offense at what I'll say, but ah well: The "differences" between styles being represented as a cultural difference between two cultures is an artificial distinction invented by foolish people who have enough credentials to be taken seriously, and perpetuated primarily by those who don't know any better.
Cultures are unique to a given region or country only until that region or country has exchanges of information with some other region or country. As soon as that happens, these "unique" features start to diffuse, and will eventually find their way to any region or country that has exchanges with either.
Sooner or later, there will not be true distinctions whatsoever. But it should be noted that the anime/manga "styles" are drawn, at their root, from early Western animation, which itself was heavily influenced by the styles of numerous Western comic strips in its inception, and which itself has since been significantly influenced by Western comic books, which were influenced by pulp fiction and are probably its most obvious literary descendant, and which themselves have come to be influenced by and to influence anime and manga.
Things such as the anime stock footage attack, generally considered an anime trope, are time-fillers and money-savers equivalent to the Filmation stock footage (if you've ever seen three or four Filmation cartoon episodes animated in the same time period, you know what I'm talking about), and are merely a different solution to the same real-world problem. The difference is that the anime stock footage attack is actually visually interesting, especially to youngsters, and so it became much more heavily used, and retained to push up the effective budget of what would otherwise be a cheaply animated piece of schlock. (It instead gets to be a more nicely animated piece of schlock.) For that matter, Filmation, whether independently or by exchange, also picked up the stock transformation idea so common in anime, and used it for the same purposes.
Hmph. Ran out of steam. This isn't worth that much of my time.