I‘m glad that the US is progressing in this regard but I just looked up the numbers for DB in Germany to have a comparison: 1.8 billion passenger trips / year and that with a population a quarter the size of the US.
Keep in mind that Amtrack is serving much longer distance routes, so this is far from a perfect comparison.
Much longer distance and they're using rails owned by freight companies who regularly violate priority rules via loopholes, so the passenger experience is sub par on many cases.
Things like... the passenger trains are supposed to have priority, but if the freight train is simply too long to fit on the side track, then it can't get out of the way so the passenger train has to stop instead. Don't need to stop if you can't fit.
DB in Germany to have a comparison: 1.8 billion passenger trips / year
Does that count city undergrounds, or is it only national rail between cities?
French SNCF claims 122 millions travellers in 2023, SNCF is mostly between cities.
RATP, which is mostly inside and close to Paris, mentions about 3 billions travels in 2023.
DB does not operate any tram, light rail or metro systems, so those are probably not included. S-Bahns might be included though, at least those operated by DB