On the other hand, when Linux was new (I switched to Linux in early 1992), you could install it all on a floppy and boot in a few seconds. Not much difference really. Just way more flexible with a Linux floppy than a DOS one.. I kept a Linux floppy around for doing various stuff with problematic PCs.
It's way more important (or was, at the time) that MS-DOS could run on 8088/8086 and '286, unlike regular Linux.
Not sure what you mean by practically usable Linux kernel. It was perfectly possible to use the < 1.0 kernels on a floppy, with enough tools to do useful work.
I'm afraid it would: in 2002 I was involved with the development of a very early wifi AP implementation at Freehosting; this was running uclinux on an ARM7 with a pretty bare kernel and the whole OS fitting in under a megabyte. Booting was already pretty much instantaneous then.
It's way more important (or was, at the time) that MS-DOS could run on 8088/8086 and '286, unlike regular Linux.