I've seen many applications re-created feature for feature just to do it in a different language. If it doesn't improve the wheel or solve a new problem, that's reinventing the wheel.
In the case of rewriting an application feature for feature in another language, that may or may not be a good idea. Maybe we're switching from an interpreted language to a compiled language because we need better performance. Maybe we're replacing a huge pile of impenetrable bash with a well organized Python app. Maybe we're taking advantage of a library that's only available in another language. Maybe there's a good reason for the rewrite but it's so much work that it's still not worth it. Maybe it's just a engineers wanting to use the latest toys because it'll look good on their resumes.
It's totally legit to question the need for a given project. But the phrase "reinvent the wheel" is just scornful insult. It adds nothing to the discussion, and in fact makes it harder to discuss trade-offs.