While it's true that these standards are X years old, the software that encoded those formats yesteryear is very different from the software that decodes it today. It's a Ship of Theseus problem. They can claim an unbroken lineage since the distant future, the year 2000, but encoders and decoders had defects and opinions that were relied on--both intentionally and unintentionally--that are different from the defects and opinions of today.
I have JPEGs and MP3s from 20 years ago that don't open today.