That isn't in tune with reality. Maybe a lot of people are lucky enough to experience a life where nothing goes wrong - I doubt it - but there are a lot of disasters in the world where a life can just fall apart. And if you love anything, you're going to lose it and that will really hurt. The options are basically suffering or a monk-like abstinence from emotion and attachment.
Someone having a chaotic, even shambolic, life doesn't disqualify them from giving life advice. That is just normal. The best and worst of us have objectively horrible existences filled with disasters. Most people don't talk about the sheer number of things that go wrong because it makes for distressing chit-chat.
Peterson does good work in being open about some of that stuff. That is part of why he is popular.
I could counter your argument and say that him pulling himself out of his recent depression is evidence that his ideas work. If a dermatologist gets an acne breakout and then fixes it, we don't blame them for the breakout, we commend them on addressing a difficult problem. Either way, this counter-argument of mine, and your original argument, are both silly. If his depression was more biologically grounded, he deserves neither credit nor blame. If his depression was due to social situations like cheating on his wife and feeling immense guilt, then yes, we can blame him for creating a depression based on his own stupidity. But neither of us knows the situation and so it's an irrelevant thing to bring up at best.
Philosophy doesn’t have to be based on individual actions and results to be helpful.
Would you say Socrates shouldn’t be listened to because his life ended in shambles? Peterson isn’t anywhere near Socrates, but I find it interesting that you would discount his information because of his personal life.
> ... There he passed his philosophy of Cynicism to Crates, who taught it to Zeno of Citium, who fashioned it into the school of Stoicism, one of the most enduring schools of Greek philosophy...
You know Peterson is a licensed clinical psychologist right? It’s literally his job to give mental health advice for money.
Or are you just against mental health workers getting paid?