I don't know about this approach. My initial thought is that you seem to have a very specific definition of omnipotent in mind, and any other definitions must be rejected because they don't fit your theory. The idea of omnipotence is pretty complex, and I don't think it's out of bounds to suggest that it conforms to logical rules like the rest of everything else seems to.

Also, I'm not saying it's logically impossible to destroy God, just that it's logically impossible to expect omnipotence to be destroyable. I mean, that's inherent in the definition of the word. Like an unquenchable fire cannot be quenched, or an immovable force can't be moved. If it's true that omnipotent means, or at least includes indestructibility, then it seems to me you're saying the term omnipotent itself cannot be a real concept because anything omnipotent would lack the power to destroy itself. So without even bringing God into it, you challenge the term itself.

At the end of the day though, if that's all God can't do then for all practical purposes He is Omnipotent because if He was destroyed then all existence would cease, and there would be no intelligent beings to debate semantics😁