I came into the industry right when XML fever had peaked as was beginning to fall back. But in MS land, it never really went away, just being slowly cannibalize by JSON.

You're right though, there was some cool stuff being done with xml when it was assumed that it would be the future of all data formats. Being able to apply standard tools like XLT transforms, XSS styling, schemas to validate, and XPath to search/query and you had some very powerful generic tools.

JSON has barely caught up to that with schemes and transforms. JQ lets you query json but I don't really find it more readable or usable than XPath. I'm sure something like XLT exists, but there's no standardization or attempt to rally around shared tools like with XML.

That to me is the saddest thing. VC/MBA-backed companies have driven everyone into the worst cases of NIHS ever. Now there's no standards, no attempts to share work or unify around reliable technology. Its every company for themselves and getting other people suckered into using (and freely maintaining) your tools as a prelude to locking them into your ecosystem is the norm now.