Where were you when you discovered that exoplanets with thick nitrogen atmospheres with earth like quantities of oxygen on habitable exoplanets arent even rare???
why the fuck doesnt everyone know about this study.
https://www.nature.com/articles/srep13977
titanium oxide (which is VERY common in regolith) naturally catalyses the production of oxygen from liquid water in the presence of near UV light. Basically any planet with even slightly more titanium oxidethan earth, with a atmosphere above the triple point of water, in the habitable zone of a stable star would accumulate earth like quantities of oxygen abiotically within the first billion years of its life and maintain it. Just for an example of how common that kind of scenario is, even the moon if it had an atmosphere would have accumulated an oxygen atmosphere with the levels of titanium oxide in its regolith. the is a decent chance even proxima centauri b right near door could have a breathable atmosphere, the oxygen would form ozone to help protect the planet from uv radiation and even a weak magnetic field could prevent the majority of atmospheric losses. There could be dozens of breathable atmosphere exoplanets within 1 dozen light years, which are reachable within 50 years with fusion rocket or antimatter-matter annihilation beam core rockets.