Sure, and sensible things like barriers at bridges makes a ton of sense because doing that doesn't negatively impact anyone and merely gives people more time to rethink their choice.

That said, even with those safeguards, tons of people kill themselves. I had a friend do it by hanging, others use drugs, and some use cops.

If we look at statistics, the US has 15.6 suicides per 100k, compared to 18.4 in Belgium, 12.9 in Germany, and 16.6 in France (not trying to cherry pick here, please look up the stats yourself). Each of those countries has (largely) banned guns, yet the US's numbers aren't all that different, so surely guns aren't a major contributor here.

What we need is to address the core issues here, such as access to mental health resources, more social interaction, etc. Banning guns isn't going to meaningfully impact suicide, it'll just shift the statistics to other methods and maybe delay it a bit. People like easy solutions, and treating the symptoms is very attractive, but it's not a real solution.

there’s a very wide middle ground of options between “do nothing” and “take all guns away”. This is not a binarry issue.

Sure.

However, most of the gun-related "solutions" I've seen wouldn't actually solve anything, or there's very little supporting evidence that they're actually effective (see this Twitter post by the RAND Corporation, media bias for RAND Corporation).

When it comes to suicide prevention, the most effective solution I've seen presented and implemented are red flag laws, yet suicide and mass shooting rates don't seem particularly impacted by that. It turns out people are really bad at taking advantage of those laws, and there's always the risk that innocent people get hit as well.

We already have laws in place in most (all?) of the country that, if actually followed, would prevent a lot of these cases (not suicide, but access to guns). You already can't own guns if you have a felony, if you're on certain medications, or have a history of mental illness. The problem is that many people don't actually get officially evaluated for mental health, don't report medications, etc, so the laws end up missing the very people they're intended to prevent from getting guns.

And then when we look at suicide statistics, the US isn't all that different from European countries at 15.6 per 100k, France at 16.6, Germany at 12.9, and Belgium at 18.4 (IIRC, guns are largely banned in those countries). The US is higher than its neighbors (i.e. Canada has 9.4, and Mexico has 7), but I don't think that's a smoking gun here since Europe also has a wide range (UK is 9.5 and Spain is 8.7). Guns existing doesn't seem like a major factor in suicide rates, it just happens to be the most convenient method so it gets used the most. If guns were effectively restricted from suicidal people, the biggest change we'd likely see would be shifting from firearms to other methods of suicide, not a significant drop in overall suicide rates (though maybe an initial drop due to delayed suicides).

Real solutions here are hard, and banning guns is comparatively easy, but I really don't think it would actually solve the problem.