This is clearly a "why not both" situation.
Emissions must be cut and new technologies for reversing existing damage must be developed. There's a whole bunch of different things that needs doing, because there is simply no single solution, but using one approach to argue against another is certainly not helping anyone.
The whole thing is an abstraction. The nucleus isn't actually tiny ball shaped things mashed together, but rather cloudy stuff which would probably not be identical if we could actually see them. The quarks that make up protons and neutrons are considered elementary particles and identical, but they don't move around much unless energy is used to split them.
The electron however is an elementary particle that moves outside of the nucleus and can move from one atom to another. So the hypothesis is that if we could follow one electron from the big bang to the end of the universe, and this electron could move both forwards and backwards in time, it would potentially be enough with just one.
It probably doesn't hold up very well, but it's an interesting thought experiment.