@Kovaelin It depends on how old the system is, sometimes there are fixes or new features added in newer releases, but they stop updating them after some time, or when the feature set is no longer being expanded (like sometimes happen when Intel releases a new processor, which a system board might support but which needs slight changes in the bios.)

So not updating it is not that risky, as it's not so frequently or continuously updated like an operating system, for example.

There's always some risk on flashing a new bios or firmware into a device -- things CAN go wrong, and it's a pain if they do - a bricked device is the result, recovering is difficult or impossible. So do it with care, and pray to the Gods that all goes well, best if you have an UPS, uninterruptable power supply, to connect the device to. Laptops, have a charged battery and do it with the power adapter plugged in as well.