It is a 12 day one way trip that includes plenty of overnight non train stays(i.e. hotels), full day sight seeing stops etc .
You can mix local car rentals to take extended side trips add much longer breaks with hop-on/hop off if you plan to do so.
There are national park themed trips specifically, or number of great regional options or other cross country journeys like LA to NOLA etc.
It will be never be perfect exact fit to your specific tastes and needs, no public transit can ever be,. However that doesn't mean it is not a great option for a traveling family vacation with sight seeing and breaks, where you can actually spend quality time with the family rather than just looking straight at the road all day, while everyone else is on the phone.
I can only say your understanding of Amtrak offerings are very inaccurate.
Amtrak offers plenty of trips with kind of features you are asking for https://www.amtrakvacations.com/travel-styles/cross-country-...
For example the NYC to SF is an itinerary goes like this https://www.amtrakvacations.com/trips/great-american-majesti....
It is a 12 day one way trip that includes plenty of overnight non train stays(i.e. hotels), full day sight seeing stops etc .
You can mix local car rentals to take extended side trips add much longer breaks with hop-on/hop off if you plan to do so.
There are national park themed trips specifically, or number of great regional options or other cross country journeys like LA to NOLA etc.
It will be never be perfect exact fit to your specific tastes and needs, no public transit can ever be,. However that doesn't mean it is not a great option for a traveling family vacation with sight seeing and breaks, where you can actually spend quality time with the family rather than just looking straight at the road all day, while everyone else is on the phone.