Lets say there is more of a difference than 4% somewhere else, why couldnt life evolve differently there?
From my understanding, they are saying that fusion is not possible in those regions, so stars never ignite. If a gas giant gets heavy enough, it would presumably just collapse into a white or black dwarf without ever igniting.
That means no hydrogen and helium would be fused into heavier elements. With H2 being the only possible molecule it might be impossible for matter-based life to form.
If these two things are changing what else should we question?
Our understanding of the universe will probably be continuously improving and evolving for as long as we humans are around to think about it.