Just to put that in perspective :

Shinjuku station in Tokyo (the world's busiest train station by passenger count) serves 3.64 million passengers per day.

https://en.wikipedia.org/wiki/Shinjuku_Station

Your numbers for that station include inter-city rail, commuter rail, and subway lines. My numbers were only for Amtrak (inter-city rail). If everything is included, then Penn Station serves about 600k passengers per day.

> The Acela has 3,442,188 yearly riders.

Divided by about 200 workdays a year and you end up with about 17,000. Even tripling that as you adjust for things and you probably have less than 25,000 semi-regular riders or better.

That's an odd accounting. Acela isn't commuter rail. I'm sure some people use it for regular commuting, but your numbers seem to suggest that's its primary use. It's not.