Yes,
about hair splitting was a poor word choice, though hair-splitting remains a very frequent activity
in philosophy. Fine gradations in distinction and meaning using the blunt tool of language is difficult.
I've been digging into the "what is philosophy about" question on several fronts.
The Stanford Online Encyclopedia of Philosophy (https://plato.stanford.edu) has a pretty good outline, as does the Basics of Philosophy ( https://www.philosophybasics.com/branch.html)
I've also been partial to digging through various library classifications and subject headings (LCC / LCSH), particularly CLASS B / Subclass BC, generally metaphysics, epistemology, ontology, cosmology, ethics, philosophy of mind, philosophy of religion, logic.
Another view is that philosophy consists (as a residual) of disciplines which have resisted formalisation under either mathematics (which has laid claim to much of logic), cosmology (now mostly natural sciences), moral philosophy (largely social sciences), and philosophy of mind (now largely a sub-discipline of psychology). What still survives today as philosophy is mostly the "messy bits".
And a tremendous amount of religion-adjacent concepts.
That's not knocking philosophy, which I'm finding quite useful, but it's a reality of the field.