Why choose to attain Nirvana when we can become Brahmas (or Bodhisattvas)?

As I understand, once someone attains Nirvana and passes away, there is no more dependant arising, meaning this person no longer manifests as a person or being in any realm. This also means that this person loses his personhood (although this personhood is impermanent and is part of dukkha). On the other hand, by achieving the first four Jhanas, a person could be reborn in the Brahma realms, which I understand to be the best beings in the universe, besides the Bodhisattvas. Of course, this is still impermanent and part of dukkha, but one could keep trying over and over to be reborn again and again in the Brahma realms. The other possibility is to become a (Mahayana) Bodhisattva, in which case one maintains his personhood also. Although a Bodhisattva is destined to become a Buddha. The question is, why should sentient beings choose to end their personhood permanently, rather than trying to be reborn again and again as the best person possible?