Just the raw parsing is a solved problem from a user's perspective, the issue arises when you ask yourself "into what" you parse or rather what the semantics of the tree is.

It even might not matter whether you parse it programmatically or not in some cases. Typically when looking at a given XML (or other data structure text representations) you can pattern match the semantics of what you see, but that is not always true, because everyone uses it in a different way, relying almost completely on schema and documentation to convey semantics, which in turn makes the format strictly inferior to JSON, which also doesn't have rich semantics but is simpler.