It's definitely a good option and it's just a conventional speed intercity service: A true high speed rail line would take about 14 minutes.
https://en.wikipedia.org/wiki/Texas_Central_Railway
https://communityimpact.com/houston/tomball-magnolia/develop...
I agree with you that it's too little too late, but at least they're trying.
The main difference is that this planning is done much further in advance (although at least the UK is well behind in terms of rail capacity construction - the UK and the US have many similarities in terms of government incompetence).
Only place that is faster is China, but they work on a different scale.
Connecting Dallas, Houston, Austin, San Antonio, El Paso, will take at least a decade, more likely closer to 15 years. There is no real scenario where it happens faster.
From El Paso you push to Tucson, Phoenix, Albuquerque.
From Houston you go to New Orleans.
From Dallas you go to Oklahoma City.
Then if other cities are smart at all and pick up some confidence about what can be done, and at a reasonable cost, you then see eg St Louis, Louisville, Cincinnati, Indianapolis, Chicago all link up. And so on.
The model for the US will be regional high speed rail, rather than massive scale coast to coast approaches. Maybe eventually you get high speed interlinking between them.
Atlanta or Jacksonville to Mobile and on to New Orleans, which gets you to Texas via Houston.
El Paso to Tucson/Phoenix gets you to Vegas. Properly that's an easy hop to Los Angeles (skepticism warranted because it's infrastructure in California), which gets you LA to Texas to Miami.
If they did it right, Texas ends up acting as the obvious central web that you can tie the country together with high speed rail over time.
We could build all of this for $400 billion perhaps, if it's done as it will be in Texas in terms of time & cost (enter the land & zoning nightmares in some parts of the country); $20b per year for 20 years (non inflation adjusted), which we can easily afford.
The same train takes 12 minutes for the ICE Frankfurt/Cologne to get from Frankfurt central station to Frankfurt Airport (9km linear distance, average 45km/h, 28mph) and then 49 minutes from there to Cologne (150km linear distance, average 183km/h, 113mph).
The latter leg is still pretty close to "populated areas" (just outside various towns along the route), but the track was specifically made for that train (taking required minimum curvature etc into account) and point-to-point connection (fewer junctions).
How many grade crossings are there on that route? This train, at least through Hallandale/Hollywood, needs to deal with a grade crossing every half mile (800m) or so. Considering the crap that went on during the effort 20 years ago to get FEC to stop using horns at certain times of day convincing people that a train should be allowed to do 100+ mph down that line is a non-starter.
That said, I can think of a fair number of places in different places in Europe where there's at-grade crossings in built up areas where trains regularly cross at around 100mph. (OTOH, there's no general requirement for horns/whistles at them.)
Some models are better off not being applied.
Is the benefit of running at full tilt in cities really worth it? You don't spend a lot of mileage traveling within a city, and cities are generally places where trains slow down and stop anyways. Combined with the very high cost of land appropriation in a city assuming fair market compensation, there's a reason why most places just don't bother with full high speed rail in urban areas.
Or for an alternative view, see https://en.wikipedia.org/wiki/Kelo_v._City_of_New_London .
In China its been used more regularly however compensation has been often ridiculously pitiful (although sometimes also quite reasonable and this has as I understand improved more recently). Sometimes we pay poor compensation in the west too though maybe not as bad.
Its also tied to China's communist past where land is for the public good (and typically only leased by individuals) as opposed to the west's 'right to land ownership' (i use inverted commas because its never really been an absolute right, even if people use the phrase).
Best practice in my view (as someone in the industry) is probably somewhere in between. I don't believe in a world of limited resources (as we are in) in indefinite rights of land ownership. I do believe however in fair compensation, which probably should be a considerable premium above an independently assessed market value (if the site was otherwise sold today, accounting for any other anticipated changes to the neighbourhood).
As a result, many states changed their eminent domain laws. Prior to the Kelo decision, only seven states specifically prohibited the use of eminent domain for economic development except to eliminate blight. Since the decision, forty-four states have amended their eminent domain laws, although some of these changes are cosmetic.[30]
The mechanisms were adjusted accordingly as the public and the politicians they voted in saw fit.