Interesting discusion.
As far as ego is concerned, i believe it is part of the template in which we incarnate into and the ultimate challenge the spirit must overcome. Once incarnated, the battle is on between ego and spirit with the goal of spirit mastering, but not destroying the ego.
The ego has many advantages - not the least being that it is materially driven and in the material plane, so it has home ground advantage so to speak. If the spirit wins, ie, sees materialism for what it is, and happily emerses itself in it while maintaining detatchment, then it wins and can progress to the next level.
I get the feeling my spirit chose the "easy" level, what living in Australia in a nondescript middle class environment. Imaging incarnating into, say, George Bush - the not so bright son of a powerful crime boss. Wow, that would be like, extreme difficulty. That particular spirit that incarnated into George Bush JR has had a pretty bad game up to now hehe.
It's all just a game
As to "enlightenment"
I believe achieving enlightenment is a challenge in itself, because it brings the ego back into play. To me "enlightenment" is knowing what the game is all about
: ie, that we live in a magical world where believe/will manifests, certainly on a collective level, but also at an individual level.
Once you have that sussed out, what do you do with that power? Do you use it to attract money and wealth? Beautiful women? Power? It's all there for the taking after all. Enter the ego..........