You’re confusing technological progress and revision with capabilitiea the thing already has or could gain without further advancement. “You said it couldn’t be done but they did it,” but they did it by building new and better technology, not by letting the thing they already had run for a long time.

Is it possible for a machine to gain sentience? I think so. But what we have isn’t capable of that and I don’t think it will be without considerable further technological development.