There are more way advanced systems for cuas, where they infuse radar and visual and acoustic plus now AI to minimize the false positives, but practically speaking, they are not bullet proof and still fail. RID (remote ID) is a way to have a cooperative communication and was mandated in US, but there are ways too to spoof it and cloak it.
Yeah RemoteID is trivial to spoof using an ESP32. Most hobby pilots I know simply don't comply with RemoteID. And bad actors certainly won't purchase a $75 device to add to their drone.
It does become a bit more difficult with consumer grade off the shelf drones because it's built in. Still defeatable by the determined of course.