What we really need again is local management on each of the routes like we had back in the 90s. That is essentially what Russian Railways does with their "Branded Trains" which are still technically owned and operated by the Federal Passenger Company (RZD Subsidiary) but are independently managed by the local divisions.
If we really wanted to take it to the extreme we could follow the Russian model completely. The "Branded Trains' get a special surcharge put on top of the ticket price because it is a branded train however trains can also loose their "branded status". Every ten years they have to meet certain standards in customer service, OTP, Equipment Standards, and food in order to keep that coveted status. Every year they hold a competition between the 16 Railway Directives for who has the best "Branded Train".
They are judged in three categories best dining car, best service in luxury cars, and best overall train. They evaluate the overall design of the train, level of service, range of service for passengers, and obviously best food. The first part of the competition is a physical inspection of the rolling stock submitted for review, with the second part a video clip of the trains produced by the local managers. Good luck on finding information to see who has the best train because it's really hard to find online, but if you can read Russian, or use google translate you can find several news articles about the competitions.
Now imagine if Amtrak would do this however I would structure it differently. Amtrak has 38 different branded services then have the long distance in one category, and the short corridors in a separate one and then do the top finalists be the top 14. We don't have nearly as many branded services as Russia does for each crew base because using their system the Empire Builder is bound to be in each competition because Seattle has it and the Cascades, same with Miami with the Silver Meteor, and Silver Star.
Give the trains local management that can decide their own food service, their own regional specific decor, manage their own customer service standards, and turn them free to make decisions that are better made on the ground than at a corporate level. It really isn't that hard to have subfleets of cars because Amtrak already has that. Sometimes substitutions have to be made which is understandable.
For instance the lounges on the Auto-Train are captive to that service. The Superliner Coach/Cafe are captive to the Pere Marquette, and Heartland Flyer. The Cross Country Cafe's are held on the Capitol Limited, and the City of New Orleans. The Business Class Superliner is captive to the Coast Starlight. So it wouldn't be that difficult to keep sleepers and coaches with local themes captive to certain routes. With the yards attempting to do the most minimum amount of switching possible it is entirely possible a car might stay stuck on a route for a long time.
Then all we have to do is find an incentive to convince employees who are naturally suspicious of competitions formed by corporate to play along.