macOS allows USB access without installing a driver, so that's probably why. The "driver" is just part of the app.

That’s how most operating systems have worked for over two decades. Most OSes support USB devices that present themselves as HID, mass storage, audio, etc. without any dedicated drivers needed. It’s only specialized devices or functionality that tends to need additional drivers.

	▲	lxgr 3 hours ago \| parent [-]
		It's not even just USB classes that the OS provides a native driver for. I believe that on both iOS and macOS (not sure about newer Windows versions), you can essentially access USB as a byte streaming device. If your app is the only one expected to communicate with a given device, you can then just directly embed the logic speaking that protocol in it. A driver is only needed if you want to provide a shared high-level abstraction to other applications as well.