Ah, well, as far as XML is concerned, yeah, these are very different things, but that's where the problem stems from. In your programming language, you don't have two variants. You just have (person (name "Alice") (age 30)). But then, because XML makes a difference between metadata and data, you have to decide whether "name" and "age" are one or the other.

And the point I wanted to make, which perhaps didn't come across as well, is that you have to write down that decision somewhere, so that when you deserialize in the future, you know whether to read these fields from attributes or from child nodes.
And that just makes your XML serialization code so much more complex than it is for JSON, generally speaking. As in, I can slap down JSON serialization in 2 lines of code and it generally does what I expect, in Rust in this case.

Granted, Rust kind of lends itself to being serialized as JSON, but well, I'm just not aware of languages that lend themselves to being serialized as XML. The language with the best XML support that I'm aware of, is Scala, where you can actually get XML literals into the language (these days with a library, but it used to be built-in until Scala 3, I believe): https://javadoc.io/doc/org.scala-lang.modules/scala-xml_2.13/latest/scala/xml/index.html
But even in Scala, you don't use a case class for XML, which is what you normally use for data records in the language, but rather you would take the values out of your case class and stick them into such an XML literal. Or I guess, you would use e.g. the Jackson XML serializer from Java. And yeah, the attribute vs. child node divide is the main reason why this intermediate step is necessary. Meanwhile, JSON has comparatively little logic built into the language/libraries and it's still a lot easier to write out: https://docs.scala-lang.org/toolkit/json-serialize.html