I'm also not convinced they help human readability that much. e.g., when I've done my own binary formats, I typically also create a "dump" utility that convert

I'm also not convinced they help human readability that much. e.g., when I've done my own binary formats, I typically also create a "dump" utility that converts the file to a readable text dump. I find the ergonomics of this are just fine for my purposes. less somefile.json isn't that much easier to type than dumpdat somefile.dat | less That said, different purposes are different. I'm not so worried about human-readability for short-lived stuff, but, if you're talking about data that may be sitting around for decades, then the human readability question becomes something you might better characterize as "future comprehensibility": If someone's trying to dust off 50-year-old business data from deep in the archives, they're going to have a much higher chance of success if it's CSV files than if it's in some custom binary format whose documentation was lost 40 years ago.