The cost seems pretty obvious TBH...they're subsidising their car industry to a much higher degree than European and American countries in order to achieve a greater market share and by extension control of large foreign car consumer markets. Given enough time, they will capture significant market shares in these markets due to artificially low prices outside of regular market competition.
There's of course also the general increased security risk of the Chinese government being plugged in to all the companies making these cars with black box software and always connected to the internet.
Not quiet, the difference is in how excessive it is with Chinese industry compared to VC backed capitalist counterparts.