Faster is something of an arbitrary standard because speed is almost always a trade off with efficiency. A lot of China's speed comes down to cheap labor and inefficiently allocated capital.
Every 6 months of US health spending above OECD baseline i.e. ~8% of GDP, aka ~2T/y buys you the entire HSR network in China, stations included. How inefficient is PRC capital allocation really? A few 10s of millions of extra housing units when they have 200-300m more people to urbanize? The point is PRC over allocates but quickly readjusts, i.e. even housing allocation basically capped in 2010s when new floor space peaked. The even more important point is PRC thinks it's important to over allocate and have in abundance than to have not enough. I argue most would prefer problems of over allocated abundance over under allocated scarcity.
Like US has plenty of cheap labour (mexicans), they just choose to exploit it maximally in some sectors (like agriculture), and partially (like construction), vs maybe maximally exploiting cheap labours in the latter would do US some good.
We can keep using that excuse, but the reality is they're building, uplifting millions of people (obviously with some problems, but with the idea of "for the greater good"), and going forward with technology. Also, labour is actually not that cheap in China, compared to a decade+ ago.
On the same note, if we only talk about high speed rails, Spain has built up quite a network as well. Not as fast as China, but still. Labour isn't cheap over there at all, but seems like they figured some stuff out.
