I feel like you're missing the point here.

P2P protocols like IPFS are built with the expectation that clients are persistent. They take a nontrivial amount of time to start up (e.g. to discover peers), and require continuous maintenance from the application to keep running (e.g. to chat with those peers and keep them happy).

These characteristics are incompatible with clients like curl. They're written with the expectation that connection setup is cheap and that connections don't require maintenance while they aren't being used. These expectations are all true of existing protocols like HTTP(S) or FTP; they fail with IPFS. And there isn't really any way to solve that without introducing another process to act as an intermediary -- which is exactly what an IPFS gateway does.