Although I’ve had sets as long as 10 years. It just depends on the set, Forged irons provide you more feel and feedback, they are softer and as such they wear out faster. I had a cast set of Callaway X 20 tours I played for 10 years. They are sitting in my garage and still look barely used.

I change woods when I start hitting them poorly too often. for me it’s like a relationship when You have enough negative experiences you know you wont trust the club and it will never be the same, it’s time to try something new. Typically every couple years.

I change wedges every 12 to 18 months since they wear out with use.

As for my Putter, same rationale as the woods above. I paid $750 for my current putter, so I’m not changing it anytime soon

Keep in mind that I play 1 to 2 times a week, so for most people you can keep clubs much longer