Uh, not to be too much of an Internet nitpicker, but according to [1] there's around 168,000 gas stations in the US. That's a pretty big car-using market right there.

Numbers for China are harder to come by, a quick search yielded [2] which states around 120,000 stations in 2019.

So, extrapolating from those two data points, I still think "millions" is a bit too many-sounding.

1: https://www.fueleconomy.gov/feg/quizzes/answerquiz16.shtml

2: https://www.businesswire.com/news/home/20190226005504/en/Chi...