If it truly hasn't been fixed for years, then either the people involved haven't noticed or don't care. If the former, filing an issue is helpful. If not, filing a patch may not get anything fixed either.
It is more likely that "the people involved" are working on other things or just don't share your concern. Filing a ticket can be helpful, but a pull request is usually preferred times 10,000. You are right, it is also possible that a change may mot get merged... In which case you've added the feature so the software is more useful to you anyway. Everyone wins.
Everyone wins if I have to maintain my own branch forever just to fix some documentation that I don't need because I figured out what was going on well enough to write a documentation update?
