The US actually has quite a bit more high speed rail, if you go by the definition of "rail that can be used at 200kph". There are >1000km lines between DC and Boston and New York and Charlotte. There's a LOT of high speed rail in the US.

Now, if you go by the definition of "lines where they actually go 200kph", there's about 65km of it, and only for a small number of trains at certain hours. That 65km is on 735km line, which is where this number comes from.

Most of the high speed capable rail is in places where the stops are too close to get up to speed properly, so it never hits high speed. Very dense areas are actually not that suitable for high speed rail, because you spend most of the time accelerating and decelerating and standing still to board. You want high speed rail in between more distant cities, not as a commuter train.

China gets that, but the US doesn't. And if you look at the rail in Europe, the trains stop every 10 minutes because they've reached another city.