California high speed rail is an actual project which has actually been building actual rail since 2008. It is the only rail megaproject active in the United States. It has many challenges, none of them physics, some of which were mad worse by Musk's bullshit.
Asking for an actual comparison between the circumstances of the Chinese high speed rail network and the circumstances of the California High Speed Rail project is valid.
This response reflects poorly
This is misleadingly reductionist. California high speed rail has made consistant progess in that time. That progress has been slower than ourslowest expectations. It demonstrates the void of expertise the US has in rail megaprojects. However, that expertise is being built, slowly and painfully. Its still forward progress for a nation which tore up half its rail overthe last 50 years.