What systems? Those like St. Louis where the trains don't have to stop at lights? MetroLink doesn't have great frequencies and may not go where you want, but they have gates and don't put up with this nonsense that cars can have priority over light rail.
It rarely shows up, when it shows up, it doesn't go where you want, and DAMN it gets there fast.
Sounds awesome.
Yes, we could do better. See London/Paris/everywhere else in Europe. Baby steps.