I do hope you're not considering the highway system as a short-term, disconnected system. Last I checked, it's been a pretty good long-term, networked infrastructure project.
How would HSR differ from traditional rail infrastructure in the modern age? Rail was phenomenal pre-affordable automobiles. I get that it was the cornerstone of America's rise to power in the 19th century. But even back in its heyday, it crumbled, pre-automobile. The over development of rail was a massive problem for the American economy due to its limitations. It's expensive to lay rail. It's expensive to maintain. It can't go in all the places roads can. Rail is niche in transportation and does what it does well, mass heavy cargo transpo to far distances, like 1k mile distances. Shorter than that, it's not really that economical. This is why you see lumber, coal, gypsum and other raw materials normally moved on rail. Or slow container goods from coast to coast. It's not used for as many goods as people think. If we, as an economy, dropped just-in-time-inventory practices, yes, rail would come back. Absolutely. But we moved to lean/just-in-time-inventory styles of production. That requires nimble transpo on accessible and prevalent paths to final destinations. Unloading train cars isn't efficient whether it's conexed or binned in small quantities. You better have ordered a few train cars worth of materials in one go to make it worth it. There's a good reason why in many industrial areas the rails are overgrown and decayed. No one uses them anymore because a semi-truck takes it straight to the commercial customer without extra logistical steps of coordination.
At that, there's the drawbacks to HSR. You only achieve those speeds on long, straight stretches. If you've road tripped the USA or worked as a truck driver for a while (I did for 7 months OTR), there are these things called mountains. It's cheaper to go around or over, not through. HSR currently can't be fully utilized at it's desired speeds with too many bends or severe changes in elevations. Semi trucks and cars do far better in these aspects. HSR would have to slow down to conventional speeds too often to see much for benefit. Trains need long braking distances in miles, not feet. As a practical example, this is the problem with the north east HSR. There are only a few stretches where it's fully utilized, giving marginal benefit to regular rail. I think it was some 20% of the length is actually "high speed".
Like, this is my big problem with people who have never worked in logistics. The articles written about HSR are best case scenarios in places that it happens to work in. Then, the general public gets a hard-on for HSR when they don't understand a single thing about the process. It's survivorship bias and dunning kruger. Hell, I know I'm barely scratching the surface of the issue at that. Yes, it works in places where the ground is flat, the population density is high and the country's gov can take land without paying for it. One of those applies decently to a decent portion to the US, but then population density there is extremely low. Then, eminent domain is an extremely touchy subject in the USA.
I'm not a fan of the angle of, "It'll improve people's lives" as some blanket concept. Not only has Silicon Valley abused the hell of the concept, "Making the world a better place through xyz", if you can't point exactly how, it's not a real argument. Which seriously, you've just been keyword dropping, not giving hard facts of benefits. You saying that makes it seem you're assuming I want to harm the general American public. Yea, I want all American's lives to improve. I completely believe HSR will not achieve any betterment. I actually think it'll harm more. You saying, "it'll help people" doesn't make all the problems of HSR okay. How does HSR improve lives more? Faster commutes, to where? No one WANTS to commute. People don't want to commute 10 minutes to work. Now it's cool to wait at a station for 10-15 minutes to get on a train, for 20-40 minutes of the commute, to then walk/taxi to their work? Then do it all over again the other direction? Hopefully you don't want to hang out with your coworkers in whatever town you commute to. Commuter rails aren't 24/7. They operate only during rush hours. People want to work in-town as much as possible. That's a better investment strategy for a city to optimize. At that, low-income jobs should not require high commute times. That's what's worth tackling, not trying to increase that distance. There have been many programs trying to transpo low-income workers to farther distances. It has always locked those people into those jobs because of the time sink of those commutes. HSR isn't going to magically fix that.
If you take Japan as an example, their HSR didn't fix commute times: https://resources.realestate.co.jp/living/average-work-commu... Over time, jobs get displaced to more centralized areas. Better paying jobs that would be in smaller cities, get sent to other cities and congregate there. Just like you have Silicon Valley and New York. Industries like to mingle with each other closely if possible. Now, you force more people to travel farther than needed. Economic competition is just going to snowball it more. If HSR is going to give us Japanese 1 hour plus commute times, no. Just plain no. It defeats the whole damn purpose.
Also, the fed doesn't just "print" money. That's a youtube cartoon understanding of how the financial system works. It's covered by bonds. Essentially loans with a few extra steps. This creates debt, which yes, is a problem. But this isn't "money printer go brrr".
Amtrak is pretty much nationalized and is a giant clusterfuck. Nationalize all the things isn't the best strategy.
And yes, this topic peeves me. It's a Haliburton like scheme for certain firms to make a ton of money off of taxpayers in the disguise of, "It's all about helping the poor people. If you hate HSR, you hate poor people." No.