A few notes, for the perplexed, that may help.

MIDI is not a sound file or a way of encoding music, not directly. It was invented as a way of getting electronic music devices to talk to each other using a common standard. Keyboards to synth modules, etc. It transmits, effectively, a series of instructions, that inform the receiving device what to do.

Of course that stream of data could be captured and put in a file, which in the early days of t'interwobble was very handy because they were small, unlike MP3s.

Nowadays, *most* things that MIDI was used for in a file format are better done using other things - notation with Sibelius (or abc software), sound using audio files, or audio hosting websites, etc. So the need to make MIDI "just work" is not there like it used to be (and supporting it properly takes a surprising amount of time and effort).