That's a good question.
We need rules to prevent exactly that. For example, computer systems such as Zoom and social media platforms should have to state clearly whether any video content, audio content or text is computer-generated, in other words by AI, or whether it is really coming from a human. We need laws to protect the public from that sort of thing.
Companies should also be incentivized to develop technology, so we are better able to distinguish between what is real and what is fake.