All that's required to show that philosophy's aim is not to eliminate itself are a few examples of philosophical questions that are not reducible to scientific ones. Naturally the author of the quoted post could still argue that those examples are in fact reducible. They'd be wrong, but I'm sure they could attempt an argument. That's philosophy.

Here are some articles from the Stanford Encyclopedia of Philosophy on the mentioned topics that should point you in the right direction to start thinking for yourself about whether these questions are reducible to the empirical sciences:

Natural philosophy

Aristotle's natural philosophy: https://plato.stanford.edu/entries/aristotle-natphil/

Hume (look at the section on causation): https://plato.stanford.edu/entries/hume/

Philosophy of language

Wittgenstein: https://plato.stanford.edu/entries/wittgenstein/

Names: https://plato.stanford.edu/entries/names/

Philosophy of mind

Aristotle's psychology: https://plato.stanford.edu/entries/aristotle-psychology/

Kant's account of reason: https://plato.stanford.edu/entries/kant-reason/