I probably phrased my question poorly. Why would I use a tool which is not or poorly maintained for a probably already outdated version of a specs, when I can use something else, that has been used for years by countless companies in productions? The advantages must be huge. And I don't know what they are.
OpenAPI is another example. There are threads on hacker news about generating code from OpenAPI specs. These always seem to say "oh, yes don't use tool X, use tool Y it does not have that problem, although it also doesn't support Z". The consensus seems to be to not generate code from an OpenAPI specification but to just use it as documentation, since all generators are more or less broken. Contrast that with for example JAXB (which is not an exact replacement I know), which has been battle tested for years.
OpenAPI is another example. There are threads on hacker news about generating code from OpenAPI specs. These always seem to say "oh, yes don't use tool X, use tool Y it does not have that problem, although it also doesn't support Z". The consensus seems to be to not generate code from an OpenAPI specification but to just use it as documentation, since all generators are more or less broken. Contrast that with for example JAXB (which is not an exact replacement I know), which has been battle tested for years.