At the time, formatting a floppy disk was a single task thing.

Downloading a file via Zmodem was mostly a single task thing.

The Windows of the day could to the latter, but not the former.

OS/2 on my 8mb 386sx could do both AND have a clock up, and play solitaire, and have another terminal window open.

It took a bit to get there, and there was swapping while everything loaded, but it was true pre-emptive multitasking, while still maintaining the highly time critical I/O stuff that Windows couldn't touch.