If you have all the money in the world, why would you need to go fast? Just enjoy the ride in comfort and style.

It depends on the route and the distance.

For example, Portland to Seattle isn't that far but I-5 can easily back up and become an hours-long ordeal, and SEA and PDX aren't particularly close to a lot of places.

It depends. I take the Amtrack from Albany to Chicago once a year or so because I hate flying. It's maybe an hour or two slower than driving and that's with a lot of time built in to the schedule for delays. The last time I took it We left Albany 45 minutes late and still made it on time to Chicago. Yes, delays happen, just like in traffic or at the air port, but I find the focus on delays when Amtrak comes up extremely over-stated. Perhaps it's just the routes I'm on.