I think the good thing about Samaritans is the small talk angle - every caller will be bringing a different type of distress. For some callers, “You are loved and matter” would make them realise they don’t want to die, for others, it would only intensify their suicidal feelings. “Don’t do it” - if the caller asked “why”, this would put the Samaritan in a difficult position. I don’t think any amount of training can teach someone to give a stranger the direct answer they need to this question
It’s more about the process of talking to someone, like with Don Ritchie, the Australian who talked more than 160 people out of suicide (he lived near a place where lots of people attempt suicide). He would never advise them, only listen and lend them an ear
Remember also that while someone like Don can physically lead someone away from the edge, the Samaritans can’t really take you anywhere, so there’s less they can do
The Samaritans didn’t solve my mental illness but they stopped me mid mental breakdown and stopped me from hurting myself. That’s not the full picture of what support should be but their role is in deescalating crises, and they do it well IME