A variable is useless because it is optimized away? I don’t agree with that terminology. The variable is useful / exists in the source code, and that is enough

A variable is useless because it is optimized away? I don’t agree with that terminology. The variable is useful / exists in the source code, and that is enough. Variables / objects only exist conceptually in the original program anyways, we just infer their existence in the compiled program by correspondence with the original code, or educated guesses about the original code.