On Android devices, without a serial console, this is often your best way to get logs for crashes happening before Android starts up enough to stream logs with logcat.

Interestingly pstore has other backends (although not necessarily on your embedded platform) such as ACPI and UEFI variables. Pretty nifty. It's one of those things you never need until it's the only thing that can save you. Definitely worth knowing the name.

I recently had to troubleshoot an issue where machines would reboot randomly in our cluster and I would never have been able to read the kernel panic logs without pstore (I assumed a power issue but it turned out to be a Ceph bug).