UEFI is already on most computers, to support BIOS systems there are separate installer entries on livecds, this increases complexity becuase system can be installed either in BIOS or UEFI mode.
UEFI is also a bootloader, rendering GRUB obsolete.
Windows 11 has dropped BIOS support, and doing so makes sense for Zorin too.
This doesn't mean dropping support for the devices themselves as UEFI can be emulated.
There are open-source implementations - OpenCore and Clover. Mostly used in hackintosh community. OpenCore/Clover can be installed with 1-3 bash commands so a script would be easy to make and ensure everybody runs in UEFI mode. OpenCore is supposedly more modern but a pain to configure, Clover should just work.
The users gain some UEFI features, the development is more streamlined, security can be improved, and improves interoperability with Windows.
On the systemd-boot side, it's a minimal bootloader made with UEFI in mind, it's just a shim. It shaves 1-3 seconds of boot time as well compared to GRUB.
- GPT parition table instead of MBR for BIOS users, enabling more than 4 primary partitions, and allows the usage of drives larger than 4TB
- better interoperability with Windows that now support only UEFI, and older releases like 8 and 10 have recovery modes on UEFI, that are not present on BIOS.
- run UEFI executables, e.g. uefi shell and more
- nicer bootloader
- SecureBoot for BIOS (WIP on OpenCore. On Clover i've had compile errors with a compile flag to enable it)
- as it ensures everybody uses UEFI, there is more incentive to create userland UEFI extensions, e.g. GNOME or Zorin could implement a "reboot into windows/ubuntu" entry from the OS, no need to look for the entry in the bootloader, or Nautilus could get a context menu for ISO images to "reboot into ISO".
- remove BIOS mode from distro installers
- work required, maybe tell ubuntu/debian/fedora to help
- opencore/clover might need more polishing
- converting existing MBR to GPT is one command on Windows, probably not so under Linux.
The post is improvised, bear the chaoticity.