One thing it can be used for is to prove certain propositions that might otherwise be hard to get traction on. Its concepts are so abstract that many different

One thing it can be used for is to prove certain propositions that might otherwise be hard to get traction on. Its concepts are so abstract that many different things can map to them. So if you can prove that something is a group, or a monoid, or whatever, then by the rules of category theory, you can now prove certain characteristics of that thing. This could wind up being a vital step in a longer proof. When this happens, it usually feels like you moved your proof forward without actually gaining any new understanding (because the concepts are so abstract). Therefore, this is often referred to as "general abstract nonsense," but in a tongue-in-cheek manner, because you actually did derive concrete value. https://ipfs.io/ipfs/QmXoypizjW3WknFiJnKLwHCnL72vedxjQkDDP1mXWo6uco/wiki/Abstract_nonsense.html https://ipfs.io/ipfs/QmXoypizjW3WknFiJnKLwHCnL72vedxjQkDDP1m...