Can you please elaborate on the Chinese advantage?

The network is massive and the average and top speeds are very fast.

China has more high speed rail than the rest of the world combined.

China's land area is approximately 25 times of Japan, def has a bigger network. But the top speed is comparable in current generations[1] except the Maglev.

1. https://www.railway-technology.com/features/the-10-fastest-h...

Comparable and essentially identical for sure, but 30 km/hr slower is slower.

Compared to their size, Spain and Japan have a largest high speed network than China.

And tickets, specially in Spain, are very cheap.

I would think that the vast amount of central/Western land in China that is sparsely populated might skew this statistic quite a bit, where Spain and Japan don't have that.

They are not. Everything is prebooked with airport-style "security" scanning. You can't even go onto the platform until your train arrives. And the experience is not quite as polished in various ways.

China is pretty good, but the only place I've ever seen proper turn-up-and-go HSR is Japan. Tap your card or phone (NFC-F, because credit card contactless is too slow for Japan), walk on. If you missed the train you were aiming for there'll be another one 7.5 or at most 15 minutes later, so no big.