I think it depends if you have issues beyond your addiction.
For me I became a heroin addict and that was the issue. There were no compelling reasons for my heroin addiction apart from naivity, irresponsibility and (initially) hedonism. Therefore once I had shaken addiction I didn't feel the need to address ptsd issues caused by abuse, a terrible childhood, etc because there were none. Perhaps that means I am fortunate.
If addiction is covering ptsd or other psychological issues then therapy might well be the answer and as the 12 step program is group therapy it might well work too.
It depends what you want from sobriety.
I just wanted to be a normal, regular adult in work with a family and living within my means.
The 12 Step program didn't provide this for me - in fact it kept me in addiction, not using but still questioning everything and constantly monitoring my behavior and not truly moving on with the rest of my life.
Normal people don't go to meetings and that is what I craved most of all - just to be a regular joe - and this is after in my 20s thinking I was special and wanting some mythical special kind of life and baulking at having a 9 to 5 and pursuing an extremely lofty and unrealistic career path.
I got clean, was lucky enough to be able to do a geographical very simply. I did a complete 'do over' at 44 years old - new country, new career, new partner, new everything - and have been good ever since. It also helped initially that my substance of choice doesn't exist where I now live.
I needed sober time to establish some responsibilities in my life as in my addiction I had zero. Now that I have responsibilities and a long period of clean time I wouldn't go back to my substance of choice even if I discovered there was a dealer down the end of my road. I have too much to lose and, more crucially, the desire to use has gone.
If you have many deep rooted psychological issues then simply breaking the physical (and less so mental) grip of addiction wont be enough to start over so therapy or AA or SMART Recovery might be great spring board into a new and shiny life.