There’s little you can do to improve the performance of an iPhone, a device that was never designed to be upgraded or tampered with. That said, there are still a few reasons you might want to run a benchmark.
Synthetic benchmarks place your device under an easy to repeat load and provide you with a score afterward. Unlike real-world usage, benchmarking tools conduct the exact same tests every time so you can monitor for any changes without having to account for other variables.
Benchmarking has been traditionally reserved for PC enthusiasts looking for a simple way to test and improve performance. This is useful when testing any overclocks that have been applied, but can also be used to gauge smaller adjustments like case airflow or thermal paste application.