OK well I had to do a search because this was going into silly territory. If you want to read some research, here's a reference list (to start):
https://forums.anandtech.com/thread...rida-gun-owners.2460058/page-18#post-38755407
Certainly some societies have higher rates of suicides than others. There is much more to risk of suicide than access to highly lethal means. However, without any doubt access to highly lethal means increases risk of suicide, and removal of that access decreases suicide. The reason why people don't simply kill themselves by other means is multifactorial. For one, suicidal actions are often impulsive or reactive or involving intoxication -- in other words very temporary mental states, so having to go out and seek a method of suicide is prohibitive. Another is that highly suicidal people often have significantly impaired energy and drive and cognitive planning capacity, so the amount of effort needed to complete suicide is prohibitive. Another is access to guns may not prevent an attempt, but the second choice of method is likely to be significantly less lethal. Another is even suicidal humans do have intact mechanisms to prevent them from doing things that involve suffering or protracted suffering, and other factors
@woolfe9998 touches on. Another is the method of suicide may be psychologically meaningful. Another is simple availability bias; when someone thinks of a way to definitely end up dead, they may struggle to imagine a method as compelling as shooting themselves. How much any of these factors have to do with someone's choice is really anyone's guess, but the data is clear, and the reasons to explain the data are abundant.
Saying it doesn't work this way is like saying it's OK to leave a bottle of oxys laying out on the coffee table while your teenager is home because if he really wanted to get high, he'd go out and buy drugs off the street anyway.