Category theory is actually a ‘simplified’ graph theory, i.e. you can see categories as a restricted class of graphs. E.G. ‘Category Theory for Computing Science’ introduces categories this way (a category is a directed graph with associative composition and identity; the free category on a graph is the graph with all identities and compositions filled in). But the restrictions (associative composition and identity) are harmless and natural for programming applications where there's always a notion of ‘do nothing’ or ‘do one thing after another’, and unlock a lot of higher structure.
But what's the utility of this definition? Does it help solve or prove something?
It helps you build an intuition for categories, if you're used to graphs :)
If you have a working intuition for categories then in most cases the specific formulation you choose as a foundation doesn't matter, just as most mathematicians work nominally in set theory without worrying about the subtleties of ZFC.
IMO the right intuition about a tool comes from applying it in the context where it provides a real leverage. In case of Category Theory that would be advanced algebraic topology (not re-phrasing basic things which are easier to understand without CT).