I live about 30 minutes from BOS by bus/rail. Let's say everything is timed perfectly: I get TSA Precheck, 10 minute curb-to-gate, 5 minute wait, boarding commences at T-20, first in line for takeoff.
That means I leave for the airport 75 minutes before my flight, fly for 1 hour, arrive in JFK/LGA/EWR, and then take about 30-40 minutes of public transit to my destination in Manhattan. And that's the ideal.
There's some break-even point for travelers between the more relaxed pace of train travel as opposed to the efficiency of air travel, but BOS - NYC is still within the realm of the train, even at Amtrak speeds.
If you can get the trains to take you directly into the city center, it can often be a better option.
That's because Boston and NYC are both navigable without a car. Only one side of the SF-LA link can claim to be close to that ideal.
But the time and hassle of airport parking and security and delays might be able to keep a 3.5 hour train ride viable even in CA. That would require a train system that allowed passengers to step through a quick scanner with no line and onto the train without queueing or carefully organized boarding. Lots of train systems used to do that in the USA but the bureaucrats don't like passengers freely walking around platforms by heavy machinery or directing themselves or quick predictable security procedures. Acela has been abandoning efficient and established traditional practices to copy instead the airports. How long are they going to stand for a train system that isn't as awful as airport security and boarding?
Since politicians can't risk being blamed for trouble, we have no ability to control the bureaucrats and every high speed transportation system will inevitably get to be as bad as airports.
If rail could be built at the same costs as in France or Japan (or even, optimistically, Spain or Korea), to wit, $20-30MMM, you could justify it just for saving the cost of airport expansion. But at $80-120MMM it's lunacy to proceed.
I live in LA and travel to the Bay for work frequently. I can walk to a Metro station from my house in Highland Park in 10 minutes and be at Union Station in 13 minutes. If I could spend 3 hours on the train to SF from Union instead of driving to Burbank, arriving an hour before my flight, and then spending an hour on a plane, I would do it every time.
You can't make a city transit and walking friendly by grafting rail infrastructure over a car-based design. You need to allow development on narrower streets without minimum parking requirements on every lot and you need more population density.
You'd have to actually change the rules and overcome the NIMBYs. Some problems can't be solved with cash.
Pretty much this, if its sub-5 story slum (aka most US cities & nearly all suburbs) overlaying rail is a bandaid. The city was built wrong in the first place, and needs to gain density, rail can keep a dense city economically viable by providing reliable, rapid transit. There is no good transit solution for suburban sprawl.
I think the point is that one of the things making train travel to, say, Manhattan attractive vs. air is that I can just walk, subway, or take a shortish cab trip to my destination from Penn Station. That's a big advantage over getting into Manhattan from any of the NYC airports.
If the answer to arriving in LA is "you need to rent a car in any case" (which it often will be), then you lose one area of train potential advantage.
I'm one of those people that go NYC to Boston and NYC to DC. I work in the dining car with laptop and WiFi. Only take planes when taking early AM flights to get to Boston or DC early in the morning.
That theory doesn't really work for LA because it's so spread out that you are very likely going to need to take a car to your final destination regardless of which mode of transportation you use to get into the city.
Depends what part of LA your in, but in most cases your absolutely right. Most areas are designed with cars being the prime transport, with sidewalks halfheartedly tacked onto high speed roads. I'd never walk along that by choice!
If you can get the trains to take you directly into the city center, it can often be a better option.