Passenger service using trains is the future because air travel is doomed due to the pandemic, which will not go away. You can distance yourself on a train ( book a sleeper!) and there is more room to reconfigure the seats, rooms and sleeper accommodations. W
Passenger rail may, indeed have a good future bu not for the reasons outlined here:
1) The pandemic will go away. Maybe not this year, or even next year, but sooner or later there will be a treatment, a vaccine, or the virus will become less deadly. (Killing hosts isn't really good for viruses.)
2) Sleepers are only available on a small percentage of the passenger trains run by Amtrak. Most people ride short distances in coach or business class, and while the seating is more spacious than airline coach seating, when the train is full (and those of us who support passenger rail would like to see the trains full and bringing in lots of revenue most of the time) there is no social distancing. Passengers who take longer trips actually have in increased risk of catching the virus because they're exposed to the ambient environment in the railcar for a longer period of time than if they flew.
3) Railcars have no more room than airplanes. Right now, it's customary for Amtrak to offer 2X2 coach seating with a larger seat pitch than current airline coach, but there's no reason they couldn't offer 3x3 seating just as cramped as anything the airlines offer. BTW, I once took the Capitol Corridor to Sacremento, and the seat pitch on those California cars was more like that of an airliner than and Superliner. Also, lots of commuter services right now offer cramped 3x2 seating.
Bottom line is that sooner of later lots people will be traveling again, and if they have to go really long distances, most of them are probably going to fly, just like before the pandemic. The numbers of people traveling will be a good bit less than before, but that might have as much to do with the recession as it does with the pandemic.
I don't think the pandemic changes anything about rail advocacy. Corridor rail service deserves support because it gets people out of cars and short-haul flights. Long-distance rail service provides access to mobility to far-flung rural communities. This provides benefits in reductions in greenhouse gas and other air emissions, reduction in traffic congestion, improved safety as compared to everybody driving, and so forth. Short-term revenue will be tight for everybody involved for a while, but ridership (and revenue) will eventually snap back.