As others said, you can do it. It's very useful for some scenarios. Bootloaders and boot managers take away a lot of the management, which is welcome with many

As others said, you can do it. It's very useful for some scenarios. Bootloaders and boot managers take away a lot of the management, which is welcome with many UEFI screens. You have some, like HP's, that will let you browse to an EFI file and/or manually manage custom entries, basically removing the need for a bootloader in most cases, and then there are the ones like my MSI board that will corrupt their own configuration if you call efibootmgr too many times and that hide any custom boot defintions from the management UI so you have to use the Linux command line to set the preference right. Whether you need one is up to you to decide. Most distros default to using a bootloader because that's what users expect, but there's no strict requirement for using bootloaders if you don't want Grub or rEFInd or systemd-boot on your system. However, if you want to do things like "edit the kernel parameters once every now and then", a bootloader is probably the way to go for most people. When you're building an embedded Linux application that will only boot kernels signed by your company, I don't see the need for a bootloader, though.