[fsckboy]

I'm no expert, but China has much, much less arable land than Europe. Something needs to finance industrialization, and in preindustrial times, food was finance because that's what supported a growing population.

[gota]

Isn't that largely offset by cultivating a lot of rice, that being so much more efficient as a crop?

What other things are at play, for example, in Japan's bonkers hight population across history?