I think a big problem with XML in most languages is the tooling around it. The libraries to parse/create it are not very pleasant to work with because of the im

I think a big problem with XML in most languages is the tooling around it. The libraries to parse/create it are not very pleasant to work with because of the immense complexity they have to deal with. If they only had to conform to a very small subset of all of XML's features and quirks, you'd have a very sane ecosystem.