cpufreq dir under /sys/devices/system/cpu/cpu* is not present for online=0 cpus

I am learning android and finding that the cpufreq dir under
/sys/devices/system/cpu/cpu* is not present when online=0 for a cpu. Why are
we hiding those directory and its content when a cpu goes offline/power
collapse ?

Because of the above, the cpu usage is not very accurate from some tools
which reads data from sysfs.

Thanks,
Ragu