There is rarely a need for GRUB on EFI systems. Create a unified kernel image, create a fat fs gpt partition, mount on /boot/efi and put the image there, then add it to efibootmgr. Sign and use systemd-stub and Shim for Secure Boot. No GRUB, no systemd-boot, just EFI firmware -> initrd -> kernel. Tried and tested on Debian 12 and Trixie. Can also dual boot Windows if the machine has a way to select an OS on boot, something most systems have these days.

I think the work required to do the above vs just using the standard installer is what holds people back, but it's hard to mess up once it's done.