Why can't we just have:

about:tabs

... which would be a plain text listing of all the URLs of all the tabs you have open ?

You could just copy and paste it to a file or whatever. No fancy bookmarking scheme needed.

Instead, we need to dig several directories deep into /Library (or whatever, depending on your OS) and then use JSON tools to export ... I've already lost most people.

Go search for "how can I export tabs" or "how can I save tab urls" and you'll see thousands of people trying (usually in vain) to achieve this very, very simple thing.

EDIT: No, I don't want to install an extension to do this.