I don't think XML is good at all for config files or UI/UX component markup, but for me that's mostly because of the end tags. Other formats, such as YAML, are

I don't think XML is good at all for config files or UI/UX component markup, but for me that's mostly because of the end tags. Other formats, such as YAML, are able to describe hierarchical data without the verbosity of end tags, and I think that makes the files much more readable. In fact, I think it's fair to say that WPF and all of Microsoft's config and resource file formats inherit their use of XML from mimicry of the Java ecosystem when C# and .NET were being developed as an alternative stack to Java. Android's inheritance is more direct, since it's based on the Java ecosystem. And as we all know, the crazy hype phase that XML went through was hand-in-hand with the crazy hype phase that Java went through. If Java hadn't happened, XML probably still would have as an improvement over SGML, but it probably would have remained the simple document markup language that it's pretty good for rather than becoming the "XML Everywhere" beast.