Since the discovery of the first radio pulsar fifty years ago, the population of neutron stars in our Galaxy has grown to over 2,600. A handful of these sources, exclusively seen in X-rays, offer a privileged view of a variety of emission processes and evolutionary channels that cannot be probed through the bulk of the radio pulsar population. The forthcoming all-sky survey of eROSITA will unveil the X-ray faint end of the neutron star population; therefore, it has the unique potential to advance our understanding of the sources that are especially silent in the radio and gamma-ray regimes. In this talk I will review how alternative scenarios of neutron star evolution (in particular, involving magnetic field decay and fallback accretion) can explain the observed neutron star phenomenology. I will also discuss the expected role of eROSITA, and the challenges it will face, at probing the galactic neutron star population.