when Sound Blaster came out with SoundFonts and the AWE32 they really made .MID files shine. Old MID files that sounded pretty bad on a previous Sound Blaster or AdLib suddenly sounded amazing.

And you think, wouldn't it be cool if the .MID contained the SoundFont? And... you get .MOD files, which were unfortunately seen as this weird demo scene format but were quietly doing things the music industry had not gotten around to yet. It was MID that would sound identical on any machine you played it on (assuming said machine had PCM playback)