Except maintain anything you just wrote.

so here I have a great IDE, lots of static analysis, continuous integration, automatic dependency management etc... people who say you can't maintain java don't know how to code in it, after 13 years it's clear to me why it's still popular.

Actually I don't think you can do everything in those 3 languages, you should try some functional programming and see the difference by yourself. Sure, all languages are turing equivalent, but some of things that are easy to write in e.g. lisp would be really painful to do in c++/java. Also none of them is suitable for replacing e.g. bash as a scripting language.

give me one example of something I can't do. of course I've done functional programming and sometimes it's nice, but I don't see it as the big advantage many people do. Algorithms and engineering are sometimes hard, actually programming is rarely the difficulty in any project.