There will never be reliable statistics on this issue.
It is a personal journey.
My father is 83yrs old.
After a particularly spectacular implosion of his life, business, sanity, etc., he was helped limping from the ashes and started a new life 20yrs ago.
No recovery program. Just a helping hand from family and friends and the local doctor. He has not drank since. There is alcohol often in the house, which angers me. I drank that alcohol when I was there. I too fell apart. I pulled myself out of the quicksand. I got a little house nearby, started attending AA and slowly, over a couple of months, stopped drinking. That was nearly 2 years ago.
Are we both a success?
I don't know.
We could be both plastered tomorrow.
As said above, the chances of succeeding are zero, if one does not try.
I do say a prayer every night for addicts, alcoholics and people with mental health issues. It is an incredible battle to overcome an invisible torment.
Statistics are pointless.
SR probably has an extraordinary success rate.
By simply giving people a window into the world of recovery.
Too end on an annoying cliche, "It is an inside job".