Just to continue the idea of all the technology being in the driver, I think most "serious" golfers who aim to compete even at the club level now have a shaft in their driver that they have "optimized", at least to some extent. They've done things like pure the shaft, tip an R to make the flex be between an R and an S, or whatever they need. They've spent time on a launch monitor with relative experts in club fitting, checking spin rates and launch angles, and often even select their golf ball accordingly.
I don't think nearly as many players do this with their 3W, or any other club in the bag, for that matter. No shock, then, that players are confident with the driver in their hand, and get results that reflect both the confidence and the technology.