If younger me had been told, "one day kid, you will miss working with XML", I'd have laughed.

YAML made me miss JSON. JSON made me miss XML.

The pattern I observe is that in old industries, people who paid the cost, try to come up with a big heavy solution (xml, xsd, xpath), but newcomers will not understand the need, and bail onto simpler ideas (json), until they hit the wall and start to invent their own (jsonschema, jquery).

same goes for java vs php/python

Definitely. And often, it's the right call, or the thing wouldn't generate any business value (such as money) at all in a reasonable time.

But boy, how messy spaghetti don't we get for it, sometimes.

(Invent their own, badly, at first. Sigh.)

I dunno, I remember the holy trinity of $, % and @ sigils in Perl as my first exposure to JSON-like objects which are the real world's answer to S-Expressions because they address the nameless tuple problem

https://www.codeproject.com/Articles/1186940/Lisps-Mysteriou...