Currently the bootloader is only updated for EFI base platforms (x86_64 and aarch64), which is done on package upgrade since the bootloader is just a file in a filesystem and owned by the grub2-efi package.

But other platforms store the bootloader as raw data in block devices, which makes it not suitable to be updated using packages so these are never updated and the user always has the bootloader that was originally installed.

And even for EFI it may be an issue and the bootloader not be updated, for example on OSTree based systems the EFI System Partition (ESP) is not part of the OSTree transaction so the EFI binaries there are not updated as a part of an OSTree deployment. More information s in the following coreos issue.

This not only makes the system less secure since vulnerabilities cannot be fixed but also makes it hard to add new features to the bootloader because it may not be possible for backward compatibility with older versions that are installed.

For these reasons a tool is needed to update the bootloader for all the platforms.