The technology used in drivers today is close to the legal limits allowed by the rules of golf. For example, maximum head size (460 cm) and maximum energy transfer to the golf ball (ADR 0.83). The good news is that because of this, drivers develop more slowly every year - until the next technical breakthrough. Your driver should last for many years, mine is 8 years old. The main reason to replace your novice driver is when it no longer fits your game. As you develop as a player, you will likely increase your swing speed. As your swing speed increases, you can benefit from a different shaft and possibly less stroke. However, the slew speed limits for each shaft are quite wide, which means that this doesn't happen within a few months.