Those are all local systems, all the cross country and intercity (for cities where their suburbs haven't merged like Chicago or the NE) stuff has to share tracks with cargo rail.

That lack of delays from cargo is also why they work a little better. One other big delay though is that basically none of the trains operate as expresses so they have loads of little stops along the way serving all the little towns along the route where little delays build up and by the end of the run they're sometimes hours behind schedule.