I'll add that firmware updates for GPUs are pretty uncommon (my current card has had zero in the 3 years since it was launched). And an AMD driver dev confirmed as much, that it is just there in case it's needed.

And fwupd is a standard way to update firmware etc on a variety of hardware that doesn't require DOS boot drives or using Windows, more commonly used on laptops and some servers and prebuilt clients. Which is obviously quite nice from a Linux user's perspective.