Some articles have something like:
Spotify has:
YouTube has:
There seems to be at least "some" attempts to clear this, but it's outdated:
https://github.com/kevinSuttle/html-meta-tags
Why no organization manages it, or maybe there is, but I have not heard about it?
Is meta is a nice bag for all 'custom' stuff? We can put there whatever we want?
Try this tool against pages such as YouTube or www.earth.org.uk:
https://en.wikipedia.org/wiki/Dublin_Core
To be honest, in the modern age it's not reasonable to have any expectation of quality when it comes to HTML.