People hate XML. Mostly because its association with SOAP. It's also not a great data format. Why would you want a data format that is hard for both computers and humans to read?
Weird JSON with schemas. To me, that sounds like a pretty good trade. I know there's a bunch of json-schema things, but none of them have the weight of a primary-source officially blessed schema system.
Wait, what ?
I design and use scripts and tools in my personal data processing and in twilio, etc., that use XML ...
XML isn't the christ child but ... it does seem useful and valuable.