I mean, does the population density in the US support bullet trains? I know that both Japan & China for example have large population density within each city (whether you live in Osaka heading for Kobe or from Shanghai to Beijing, you get the picture) plus the governments of both countries invest heavily on the infrastructure including maintenance.
Distance is another factor between destinations, like from Nagoya to Kyoto it’s only 130km (80mi) and the commute by bullet train is 33 minutes while from New York to DC it’s 226mi taking you 4 hours by car but via bullet train, the commute time is less than it would be from driving alone. The cities in Japan are closer to each other by comparison.
China is a large country (not big as let's say like Russia in terms of land size) alongside varying topography and climates (they can still install tracks in uneven terrain but adjusting how they are installed), although their population is larger than the US (they have about more than 1.4 billion people as a country while the US is about 348 million).
The taxes work differently across countries, like in both Japan & China: they have the funds gathered from taxation allowing them to maintain constant upkeep or make further improvements. Well, what does the US government spend their taxes on? That in itself also lies the question whether the taxes citizens are already paying are worth it.
Taxes exist in all countries regardless, as governments need funding to maintain and improve infrastructure, roads, schools, hospitals, etc. The real question is: how is the government using that money? For example, in Japan the reason why public transport is considered reliable is due to their government using people's taxes for upkeep & bullet trains.
the situation in the US is multi-layered.