How did most of these former Anunnaki (now human) escape continued reincarnation in that civilization? Did they graduate? In spite of the harshness, did they manage to spiritually outgrow their surroundings?

In the earlier stages of the corruption by the fallen angelics, there were still Anunnaki beings of distinction and spiritual alignment among many who were becoming corrupted and lessened as a consequence. That has become rarer and rarer and currently it is almost impossible for an Anunnaki being to turn its life around and seek something better that is based on spiritual principles. Whether or not there is awareness of Creator, divine principles can be embraced simply because they are good ideas and are a positive influence that leads to the betterment of all, but to see those virtues and embrace them requires some inner capability to be in a vibrational alignment with the divine to some extent, and that is what is lacking in most of the extraterrestrial beings. So this will only happen when there has been some divine intervention to enable healing sufficiently to restore enough awareness to create a bridge to love once again, at least in a small way as a small beginning along a return path. This is what humans can achieve using the Lightworker Healing Protocol to start converting extraterrestrial beings to consider other alternatives for their conduct and other strategies for achieving their objectives in a way that can be more a "live and let live" perspective, and that will be a start to right the wrongs they have brought to your world. They cannot do this on their own at this point in time so it will be essential for humans to carry the burden and point the way and do the legwork for the divine intervention to succeed. Those who have escaped their world have done so through personal choice and meeting certain criteria for acceptance into an alternate role. That is what has happened to create the divine human to rework the soul expression to a new configuration that draws on the roots, many of which were present in prior lifetimes among the Anunnaki, the Reptilians, or the Arcturians, but are now refocused into a unique species built on a composite of characteristics from those and other races. So in a sense it is a reworking of the individual to create a compatibility as a warrior for the light, and they started out at the very beginning as divine beings. When set upon by the dark extraterrestrials, they were also corrupted by dark spirit attachments and it was a combination of these negative influences that began the downward spiral currently playing out. This has had a very long history and a dynamic waxing and waning of spirituality on the part of the divine human. You have come from behind many times and surged into greater power and effectiveness to counter the evildoers and then each time they have found a way to undermine humanity and create a darkening once again. You are nearing another turning point when things will be decided perhaps once and for all on the matter of human survival and ascendency where you will have won the contest and created enough healing momentum to change the direction of things for the Milky Way Galaxy as a whole and will begin expanding your scope to many other parts of the universe with new roles to play. That is the positive future available to you and is very worth fighting for, but fight you must.