Chinese new year, more people travel in China than the whole of the USA, homecoming notwithstanding. It's mass transposition, there and back again.
They need trains. I've used them shanghai to Beijing, great service. I wish I'd been able to use the maglev in shanghai
You can make more economical runs per month with trucks than with trains, meaning you get to have less stock on hand as a buffer on both ends.
This has many knock-on efficiencies - fewer resources tied up in goods, lower insurance expense, lower warehousing cost, and above all: a more flexible and responsive supply chain.
building out passenger rail frees up capacity for freight on old rail :)
this is actually a big reason HS2 in bongland is (was) getting built
Only if the high-speed rail gets used by passengers. If it's unaffordable, people won't use it.