So many assumptions here. The big one is that humans cannot change their physiology.

Another peculiarity of the argument is that while rotating rings are mentioned, they are dismissed. If you have a rotating ring of, say, a few hundred meters or larger, it is actually very suitable as a form of artificial gravity. I will point out that all of us on Earth are rotating right now, as the Earth rotates.

Another assumption is that we understand all of physics. Yet we clearly do not. The elephant in the room is the General Relativity and Quantum Field Theory are inconsistent. We also have no clue what consciousness is. And no one has made sense of what created the universe. So we clearly understand very little about the universe, and so grand conclusions about what we can never do seem premature.