How accurate is the Human Benchmark test?

[nohasm191]

The https://human-benchmark.org
Reaction Time Test is an online tool designed to measure how quickly a person responds to a visual stimulus. Typically, the screen changes color, and the user must click as fast as possible once the change occurs. The result is measured in milliseconds, giving an indication of reflex speed. It is widely used for fun, self-improvement, and even competitive comparison.