My Great Grandfather, Grandfather's, Dad and most of my childhood friends served. My ex is retired army.
My Grandparents and Dad were in a corp (Granddad and Dad REME). One Granddad made spitfires and was Navy (in fact both his brothers were too).
Friends were a mix of corps and infantry, also a mix of Officer and Other Rank.
My ex was infantry, was 'other rank'.
My Dad (I'll ignore older than him) was treated incredibly well by the army until he left and they forgot to ask him to re-sign until age 55 until the day after he left. 🙄 He saw the Falklands, N.Ireland, and the first Gulf War. He loved it so much he went back to work for the MOD to instruct and continued to do so until he retired. No mental health problems, no drugs, no drink, no tattoos, no violence. Long and happy marriage. In fact most of his friends who served with him did/do have long & happy marriages.
My generation. Lots of conflict, most on the front line (bomb disposal - eod), infantry, etc. When my ex deployed to Bosnia he saw things that I will not repeat here because its not an image I'd ever want to give anyone. Iraq, Afghanistan, Sierra Leone all bloody awful. Of course more wars reported on the TV and on SM. Most of my friends have been divorced. A lot of that due to shagging around over violence.
Mental health is now taken more seriously, but not seriously enough which is why there are so many forces charities like combat stress.
When leaving you may get courses but you get very little help. So for a career soldier who has no profession apart from how to shoot a gun and tab 30 miles in x time it's awful and probably why we have a problem with veterans homelessness, suicides, mental health problems, etc.
They have changed the contracts they give serving personnel now, their pensions, etc. The government have given them additional insecurity which doesn't help.
Not sure this answers your question. I think I've been fortunate everyone I know who has served has gone on to a better life afterwards, with the exception of my best friend who Tony Blair sent to his death.