The public, press and government can pay as much lip service as they want toward "caring" for their veterans. But that's all it is. Some momentary hand waving and noise whilst there's a new story making the circuit about the most recent veteran failure. Five minutes go by and it's a forgotten issue again.
We've treated service members as consumables publicly since the Vietnam war. For those who come back broken, not much has changed since 1955.
I know a lot of messed up vets. I've watched them struggle with their issues while fighting a broken, uncaring system. I've been aware of many enlisted suicides over the years. I know when I was self destructing I was lucky to be in a really good financial position and have a caring and resilient significant other. Without those two things clearing paths for me (which has still been a disappointing, frustrating slog) I'm pretty confident I wouldn't be here right now. If I had to rely on the VA or any other "programs" I probably would have ended up scrambling my own brains about 4-6 years ago.
Mental healthcare for veterans is clearly grossly inadequate. Lobby your representatives for better support and keep lobbying until something changes.
If you're concerned about the mental wellbeing of someone you know, act early. Don't let your doubts stop you from acting, don't fall victim to wishful thinking. Talk to them and listen to what they have to say. Keep in touch, even if they're becoming more distant. Encourage them to seek treatment. If you're concerned for their safety, call an ambulance. Find out what your state laws are on involuntary commitment, just in case.
I'd highly recommend taking a course in mental health first aid. These courses are widely available and usually free. In just a few hours, you can gain the skills and confidence to help someone in a crisis.
https://www.mentalhealthfirstaid.org/