XML has been "spooky old technology" for over a decade now. It's heyday was something like 2002.
Nobody dares advertise the XML capabilities of their product (which back then everybody did), nobody considers it either hot new thing (like back then) or mature - just obsolete enterprise shit.
It's about as popular now as J2EE, except to people that think "10 years ago" means 1999.
I kind of miss SOAP. Ahead of its time? Probably not, but I built some cool things on top of it
It's not the hot new thing but when has hype ever mattered for getting shit done? I don't think anyone who considers it obsolete has an informed opinion on the matter.
Typically a more primitive (sorry, minimal) format such as JSON is sufficient in which case there's no excuse to overcomplicate things. But sometimes JSON isn't sufficient and people start inventing half baked solutions such as JSON-LD for what is already a solved problem with a mature tech stack.
XSLT remains an elegant and underused solution. Guile even includes built in XML facilities named SXML.
For me, even when it was first released, I considered obsolete enterprise shit. That view has not diminished as the sorry state of performance and security in that space has just reaffirmed that perception.
20 years old means 1980!
Obsolete enterprise shit I guess includes podcasting. Impressive for the enterprise.
I’d be very curious what lasting open formats JSON has been used to build.
XML is used a lot in standards and publishing industries -- JATS, EPUB, ODF, DOCX/XLSX/..., DocBook, etc. are all XML based/use XML.