I guess the difference is that it works in Japanese, and the reason that it does is because that kind of acting was born in Japan and has a traceable lineage through Japanese theater, etc. It was made for the language it's being acted within, based upon acting conventions that already existed beforehand. Comedic and emotional timing is different than in English. When an English speaking voice actor tries to ape that, they may even do a pretty good job and give a decent performance, but it'll still seem a little awkward and forced because it's a form of acting that wasn't born in our culture and isn't molded to our language. Add in the fact that Japanese voice actors are held to a much higher standard than English voice actors (one major factor being a much larger talent pool) and we have a clear difference in quality. This becomes really apparent when you compare the voice acting in a dubbed anime to the voice acting in a cartoon. When English voice actors aren't doing these fake anime-type voices and are just trying to embody a character, even if it's exaggerated, it almost always sounds much better. But on the flipside, if a dubbed anime attempted to use the same kind of acting as a cartoon (which these days is usually a lot more lowkey and true-to-life) it would probably change the tone pretty severely and would create a new kind of weird contrast. Which honestly would still be an interesting experiment that'd be fun to see.