That's a pretty loaded statement. You're probably thinking of those ostentatious fools who end up in the news like "man was prevented from jumping off the bridge". Not every suicide does it on a whim, some think about that decision for many years.
As a general trend, when you make effective suicide less convenient, e.g. switching from lethal gas to carbon monoxide free natural gas in ovens, they happen less often. Not necessarily because of fewer attempts though.
That's a pretty loaded statement. You're probably thinking of those ostentatious fools who end up in the news like "man was prevented from jumping off the bridge". Not every suicide does it on a whim, some think about that decision for many years.