No it isn't, XML is an ecosystem with things like dedicated transfer protocols (EXI), schemas (XSD), transformers (XSLT) that JSON still doesn't have standardized/normalised even though JSON has been the norm for nearly 20 years. There's some projects of course (JSON Schema, OpenAPI), but they're separate and not part of the same standardization committee.
As someone who works with JSON every day and almost never deals with XML directly, it’s important to realize saying they are the same is like saying a pocket knife and a Swiss army knife are the same because they both have an extremely useful tool (and why would anyone ever use the thing with all that extra stuff I never use?). Not a perfect analogy but the one I think of for simplicity.
Back in my day, real cowboys wrote their papers in PostScript, making their papers as inaccessible as possible for user of consumer-grade devices. /s
PS won on human readability and editability but lost on portability to Adobe's own internal competitor, PDF, and because it fought and lost to (La)TeX -> PDF & (La)TeX -> DVI -> PS.
PS: I once printed out and bound the PDF 1.3 spec[0] on 24 lbs. bleached dead trees on an HP LaserJet IIIP with over a million page count. Some of the nuclear engineers and scientists an office containing <50 people routinely printed thousand page documents every week.
Other way around works too (I gave an example above), it's just not pretty in either direction.
XML makes sense for open-ended, human-written things like documents or apps. It doesn't work so well for APIs and other machine-read/written things where you'd normally use JSON.