DOS on 386ex is still used on old style taxi meters and eftpos terminals that are still being made today. The near real-time support means that even the cheapes

DOS on 386ex is still used on old style taxi meters and eftpos terminals that are still being made today. The near real-time support means that even the cheapest processor can read things like the pulses from the odometer without any misses, the version of DOS used is kilobytes in size so the components needed cost next to nothing and it boots up instantly (partly because the bios for the 386ex jumps straight into DOS without the memory and drive checks that a full blown x86 bios has). Sure you can also get a different embedded solution but you're going to be writing bare metal. DOS is a nice step up for these very low level use cases and very easy to develop for.