My impression of these services are that they are simply available so people can feel they have "done something" about someone who seems suicidal by giving them the number, then wash their hands of the rest of it. Not that someone else's mental health puts any particular obligation on you, but that's the dynamic I see play out. I've called these services twice over the years when I was young and naive and had friends…
This means that, while your experience totally sucked, it can't be generalized. Most people I've talked to from all over the country genuinely want to help. I assume it's the same in the US. But some centers offer very little training, and their legal means probably vary a lot by location.
That said, there is a lot they can do beyond calling an ambulance, but it still comes down to talking and guidance, no one can physically force people to get better, except maybe some institutions (debatable).