Wheels are low-hanging fruit for reducing the bike's weight and they're easy to swap from bike to bike. Some people swap wheels for different rides, a light set for climbing, an aero set for time trials, and so on.

Other than that I can't say that you could expect an appreciable difference in performance from wheels. I understand the impact of rotating weight on acceleration and handling, and you can "notice" a difference with lighter wheels, but whether what you notice is an actual gain in performance and handling, other than the bike being lighter overall, I am unconvinced.