The groundwork has to be made for any technology to be created, and enabling "the nervous system to receive a different response to the real stimulus" sounds like impressive progress to me, even though there's still clearly a lot of work that has to be done before full dive virtual reality can be developed.

Also, I'm "hella" excited for full dive VR, and assuming the worst case scenario is inevitable (which I think is unlikely) is just a lazy way to justify not thinking about it for whatever reason. All technologies have risks, so it's important to make them all as safe as possible.