The main reason to use powers of 2 is in the way existing hardware and software are made, there isn't any purely mathematical reason. CPUs, GPUs, memories and internal buses all use size that's power of 2, since that's the most efficient way to address them.

The main reason to use powers of 2 is in the way existing hardware and software are made, there isn't any purely mathematical reason. CPUs, GPUs, memories, and internal buses all use a size that's the power of 2 since that's the most efficient way to address them.