The history of document file formats:

1980s: I'm going to design my own proprietary binary file format using my own proprietary disk format for this one proprietary computer vendor

1990s: I'm going to design this really efficient binary file format for use on all computers. It won't be documented, but it'll be reverse-engineered without TOO much trouble.

2000s: I'm just going to schlep all of the data structures in memory into an eldritch-horror XML format and encapsulate that into a zip file. I'll have our imps, I mean, engineers create a script to convert parts of the source code into an "open format" specification that requires fifteen reams of paper to print out.

2010s: Lol cloud go brrrrr! <inserts crayon into nostril while eating glue>

2020s: 2000s, are you OKAY? Do you need a... rabies shot, or something???