Speaking as a hardware engineer, the moat did not vanish. You have simply assumed you were on the right side of the moat this whole time when in reality you dug half a trench and threw a glass of water in it.
If your firmware is open for someone to reverse engineer now, it has always been open. The real moat is firmware security, encryption, secure locked down hardware. Nobody, not even LLMs, can reverse your firmware if they can't obtain a cleartext copy of it.
You must use microcontrollers with security features, encrypted firmware, secure key stores. If you don't, you never had a moat in the first place. Your only security is the belief that it's too much effort to reverse your product. Security through obscurity is the moat that has vanished and everyone has been screaming for decades that this is not secure by any stretch of the imagination.
If your firmware is open for someone to reverse engineer now, it has always been open. The real moat is firmware security, encryption, secure locked down hardware. Nobody, not even LLMs, can reverse your firmware if they can't obtain a cleartext copy of it.
You must use microcontrollers with security features, encrypted firmware, secure key stores. If you don't, you never had a moat in the first place. Your only security is the belief that it's too much effort to reverse your product. Security through obscurity is the moat that has vanished and everyone has been screaming for decades that this is not secure by any stretch of the imagination.