I'm not aware of any bootloaders that support encrypted /boot with LUKS2 aside from GRUB. GRUB itself didn't support LUKS2 until 2021, I believe; I imagine there are many people using versions older than that.
Even with newer versions, some (many?) distro installers still default to using LUKS 1 for the root partition anyway. As the article also says, while grub2 does support LUKS 2 now it still only supports pbkdf2, so having root be LUKS 1 makes it harder to accidentally switch away from pbkdf2.
Arnavion|2 years ago