Lets quickly check Wikipedia
China:
Total length: 155,000 km (100,000 km electrified)
Total passenger/km: (1,470.66 billion passenger-kilometres, 2019)
Total freight: 3,018 billion cargo tonne-kilometres (2019)
US:
Total length: 257,722 km (160,141 mi) (I can't find figures on electrified length, seems at most 2000km?)
Total passenger/km: (10.3 billion, 2014)
Total freight: 1.71 trillion short ton-mile, approx 963 billion tonne-kilometres (I used wolfram alpha for that conversion)
So if my calculations are correct - which they may not be - on fewer rails China transports an order of magnitude more passenger and freight traffic.