Standard for civilization levels: Gu Tao quickly adapted the original Centaur standard, starting to quantify evaluations for each civilization system. Overall, it's like taking a professional title exam; once a civilization reaches a certain level, it can proceed to an upgrade evaluation test and, upon passing, access a higher level of technology sharing.
As for why we don't just unlock all technologies directly — jumping ahead in technology can easily lead to issues, even world-ending ones. For example, if we gave anti-matter energy, claimed to be the most stable energy in the universe, to a fifth-layer civilization like Earth, the best outcome is they can't make anything out of it; the worst is they blow up the damned thing with destructive power beyond measure, saying goodbye along with humans, and Earth enters another cycle.
