Grub is just unnecessarily complicated. Simpler options exist (even ones with the same level of flexibility, though I am most familiar with embedded options the

Grub is just unnecessarily complicated. Simpler options exist (even ones with the same level of flexibility, though I am most familiar with embedded options there: Something like barebox shows an alternative approach that could be applied to desktop: basically just make a shell environment in your bootloader to script your more complex requirements). But 90% of users nowadays can just use systemd-boot.