Sounds like he was a good guy. Some times the explanation is simply the “dark side”. Sad.
People kill themselves for one reason : They lose hope that the future will get better. Hope is what keeps people going.
You can take someone contemplating suicide, drop them in the deepest forest with a backpack and they will try to walk out. They will try to save their life because they have hope it will get better if they do. They will thrive better in a difficult ordeal than in an easy(boring) life.
It would shock you how many people thru-hike the Appalachian Trail because the alternative was to kill themselves. They speak of it in their trail journals.