MS-DOS was a reasonable bootloader for Linux and Windows 95; I imagine FreeDOS might be a better one if you wanted to do hobby OSDev. Historically you could get hard real time performance for things like controlling steppers from your parallel port under MS-DOS, but nowadays you'd just use Freeduino or an iCE40. Also maybe brushless motors.

FreeDOS is no good at all for booting anymore, since BIOS support is increasingly rare. No way to boot FreeDOS (or MS-DOS) from UEFI. And of course also no point in trying to run it on ARM or any other non-x86 CPU. Looks like the future for FreeDOS will be to run in virtual machines only. A bit sad, since running FreeDOS on the bare metal of a 21st century computer (even one from 10-20 years ago) has been a nice way to experience just how fast modern hardware is.