Yeah, I honestly don't know if someone who hasn't been suicidal can understand. I know my best friend hasn't been, but his dad, and like a dozen others have been--and he only could understand the analogy of depression-suicide like airplane in holding pattern is your normal state, sometimes it goes higher, but is always in holding, refueling plane are antidepressants, landing/etc is death.
And even then, he still doesn't get how people could entirely, and he's lost one friend to suicide.
I mean maybe like "picture your mother died, now picture that repeating non-stop forever, got it? good, that's your happy state, it only gets worse"
And really that's probably not the best way either lol, but it might be shocking enough to get through to them.