You have probably seen forgotten merge code, a faulty ctrl+s that has stored a s in an xml file, an accidental copy/move of code when scrolling with mouse, which have been found after code pushed to server when something isn’t working correctly. Code is compiled and will give you a compile error, but XML won’t, and a lot of systems today rely heavily on XML configuration

I have the habit of putting the “xml-maven-plugin” plugin to my maven projects which makes XML code to be validated every time it builds, this way I can be sure that nothing has been accidentally added to a file.