I see where you're coming from here - to my mind there's 3 issues here. 1 - The increased complexity of the UEFI stack having many components, and no good simp

I see where you're coming from here - to my mind there's 3 issues here. 1 - The increased complexity of the UEFI stack having many components, and no good simple explanation of it to bring people up to speed with (at least that I'm aware of) - UEFI boot introduces NVRAM which is a fairly big change from the old way, and introduces the ESP partition for storing bootloaders. Fairly significant changes, coupled with not every UEFI firmware (i.e. BIOS) implementing things in the same way - not every motherboard gives the same options to users for managing boot entries in NVRAM. 2 - The introduction of secure boot at the same time, and the confusion around shim and similar for running Linux. Don't start on the complexity of enrolling your own keys and how some motherboards let you do it directly, while others make you use keytool or another efi binary to do it. 3 - Bootloaders becoming more and more complex as a result of secure boot requiring them to sign all their code, pushing them towards external configs and modules, coupled with multi boot becoming a native feature since the ESP-based loader needs to find the right config and load it, then find the right filesystem and go from there. Much of the parts of part 3 were needed for LILO and MBR, but it feels like fewer moving parts were in play.