Amtrak is actually a government program that helped save passenger rail after it became unsustainable with the private companies. It's a fascinating history that they simply don't teach the general populace.

In October 1970, Congress passed, and President Richard Nixon signed into law, the Rail Passenger Service Act.[26] Proponents of the bill, led by the National Association of Railroad Passengers (NARP), sought government funding to ensure the continuation of passenger trains. They conceived the National Railroad Passenger Corporation (NRPC), a quasi-public corporation that would be managed as a for-profit organization, but which would receive taxpayer funding and assume operation of intercity passenger trains.[7][27][28]

There were several key provisions:[29]

• Any railroad operating intercity passenger service could contract with the NRPC, thereby joining the national system.
• The United States federal government, through the Secretary of Transportation, would own all of the NRPC's issued and outstanding preferred stock.[30]
• Participating railroads bought into the NRPC using a formula based on their recent intercity passenger losses. The purchase price could be satisfied either by cash or rolling stock; in exchange, the railroads received NRPC common stock.
• Any participating railroad was freed of the obligation to operate intercity passenger service after May 1, 1971, except for those services chosen by the Department of Transportation (DOT) as part of a "basic system" of service and paid for by NRPC using its federal funds.
• Railroads that chose not to join the NRPC system were required to continue operating their existing passenger service until 1975, at which time they could pursue the customary ICC approval process for any discontinuance or alteration to the service.

Of the 26 railroads still offering intercity passenger service in 1970, only six declined to join the NRPC.[31]

The original working brand name for NRPC was Railpax, but less than two weeks before operations began, the official marketing name was changed to Amtrak, a portmanteau of the words America and trak, the latter itself a sensational spelling of track.

source

or just do any of the many examples that the rest of the world is successful with. HSR in America isn't actually High speed rail anyways

Amtrak's Acela is the United States' only true high-speed rail service, reaching 150 mph (240 km/h) over 49.9 mi (80.3 km) of track along the Northeast Corridor.[2] Acela trains will reach top speeds of 160 mph (255 km/h) when new trainsets enter service in 2024.[3] Other services, like Amtrak's Northeast Regional and Brightline, have a top speed of 125 mph (200 km/h) and are usually not considered high-speed rail.

Brightline, while marketing itself as high-speed rail, more closely meets the definition of higher-speed rail. Despite having a top speed of 125 mph (201 km/h) along 20 mi (32 km) of newly built track, most of the route is limited to a top speed of 110 mph (180 km/h) due to the presence of grade crossings.[4] link

Brightline is the company which received the funding for the California-Nevada HSR, it's a public company that's already coming under scrutiny for their practices and costs vs their projections. I guess I need to do a write-up to link to whenever the HSR comes up with the infrastructure bill.

edit: forgot to add link for the wiki I was referencing.