Several things. First, this is the quickest thing I could find about the economics of fascism, on wikipedia:
Mostly, what happens, is everything becomes nationalized and driven by an autocratic government. Large business interests become merged (and indistinguishable from) government interests. Economy is heavily regulated to favor big business interests over those of small businesses and average citizens, and small/private enterprise is largely discouraged.
This is precisely what we see in China.
Their economy is very heavily regulated and dictated from the top. They don't actually have much economic freedom, unless you think "economic freedom" is synonymous with "big business interests". They definitely don't have anything even remotely resembling "laissez faire" capitalism that you appear to favor.
And as far as "making us rich", they do so through the wide availability of very cheap (to us) labor. What they are supplying, along with India, Indonesia, and other places we outsource a lot of labor to is the 20th/21st century version of slavery.
It's not surprising that having de-facto slave labor to minimize costs and maximize profits would make U.S. and other first world corporations rich. It certainly doesn't mean anything positive about the countries supplying said labor, or the living conditions in those countries. In fact, as labor costs increase in those labor-supplying countries due to getting foreign money, corporations increasingly look for other, cheaper, places to outsource to. Nobody benefits from this system except the already very very rich who control the profits of these corporations.