Just before the pandemic, my wife and I took the train from Chicago to Seattle to visit her brother. We got a roomette on the way out, but it was a tight fit for two people, so we upgraded to the full room for the ride back. If you have a room or roomette, the meals in the dining car are included - otherwise, you pay a hefty price for food. The food was pretty good and the beds were comfortable enough. If you can afford the full room, go for it. It makes a huge difference.
When you go to the dining car, they'll seat you with other people until each table is full. That's good or bad, depending on who else is at your table. We met some people who were interesting, but a few who I'd prefer not to talk to again. But if you have a room/roomette, they'll deliver your meal there if you want.
We enjoyed it and we're glad we did it, if only for the experience. I'm not sure I'd do it again, but I wouldn't rule it out either. I've heard the route from Chicago to San Francisco (via Denver) is the most scenic Amtrak route.