Re: Makes me pine for the days of XML...
"Which problems did XML actually solve? And which ones did it create?"
I like a good cynical comment as much as the next guy, but XML is the go-to structure for highly complex formats that have to be communicated between systems, and it works exceedingly well for that, provided the data definition was designed well in the first place. Which, yes, is dependent upon the skills of the designer (not necessarily a coder, although it helps).
So it creates no more problems than that found in most computing standards..
For small configuration files that were slightly more complex than an INI file, XML certainly looked like too much, but I feel that was overreaction (it's not hard to simplify the tagging), and in any event it became irrelevant when JSON appeared on the scene.
YAML, the format that isn't terribly readable, and fragile to boot, just wasn't a good idea.