In fairness, although Linux supported EFISTUB for ages, until quite recently, UEFI implementations on consumer motherboards were total crap.

This is what actually gave bootloaders a lease on life.

I had, about 14 years ago when Linux already had EFISTUB, a Gigabyte UD3 motherboard that had such a poor UEFI that I had to rename the GRUB executable to have the same name as the Windows boot loader; otherwise, it would forget the option after a single reboot.

Also, when using EFISTUB for the first time, I was quite uncomfortable with the kernel being stored on a finicky FAT filesystem, which happens to be a requirement for the EFI boot partition.