Golf irons wear out over time. The clubs where you are going to be most often. Do golf irons wear out? The sticks that will most often be the ones that wear out first. This is because they are the ones that hit the most.
For an average golfer who plays golf several times or practices several times a week, you should get a good 7-10 years with a set of irons. McKee says that when the irons and wedges lose their grooves, the ball loses its effect when it enters the green. So, if you've had a sand wedge for years and you've noticed the ball bouncing and rolling instead of bouncing and spinning, you probably need a new wedge. Irons are not going to lose their strength, for the most part they are just bits of metal.
There is no evidence that golf clubs deteriorate over time. Well-maintained clubs will last a lifetime. If that's the case, the answer if you want to improve is to spend more time on the practice street than in the golf shop. Seriously though, unless you wash your iron heads every night in an acid bath, golf clubs aren't going to deteriorate, especially in the hands of an amateur.
Golf clubs surely don't change that often and I've always been a firm believer in improving through the practice street rather than through the credit card. Golf equipment technology is advancing at a rapid pace and manufacturers release new irons annually, at worst every two years. If you're a golfer who hits the ball too low and you play with old golf equipment, it's likely that the new equipment can change the rules of the game. Or if you look in your bag and you still see an old iron 3 and 4 in there, you're certainly not taking advantage of advances in golf technology.
For the most part, forgiveness-related performance won't suffer as much, and irons may still feel good and worth keeping in your bag. Of course, that's a legitimate option, but some golfers are wary of custom adjusters, thinking it's a fair way for manufacturers to sell more clubs more often and complain that when they go regularly they seem to get different results every time. For the golfer who plays golf every day of the year, it can only take 3 to 4 years before a set of irons starts to lose some of its jump from the face. After years and years of hitting the same clubs in the same places, hundreds of shots a day, the irons have started to wear out.
Advances in iron technology haven't been as dramatic as they have been with drivers either, meaning your irons are unlikely to become as old-fashioned as other clubs. However, if you are satisfied with the “performance” of your existing irons and maintain them well, checking that the grooves are good and making sure that the club face has no obvious damage, your irons should last a long time. While there have been advances in putter technology in an effort to make them more balanced and therefore give golfers a better chance of keeping their putts on target, it's hard to argue that the changes have been devastating. When the newest irons are constantly outperforming you or your clubs start showing physical signs of wear and tear, you know it's time to put that new set in your bag.
Golf irons wear out over time, but thankfully it has more to do with how often they are struck, their quality, and how well they are cared for than over time.