system
Given the following post, respond as if you're commenting on Reddit:
human
[Assassin's Creed] Why are the precursor race obsessed with parkour courses? And what makes assassins (and templars) so good at them?

In Assassin's Creed: Brotherhood, at the end of the game (SPOILERS) you go to a church and (surprise surprise!) there's a hidden parkour course there, built specifically so you can get to a hidden vault, the secret temple of the precursor race, which contains another parkour course which you run on to activate the apple container.

Who built the modern course?  Why is there a link between assassins and parkour?  Why do the precursors make this oddly specific link?  And finally, why are assassins so good at parkour?  I don't think I've ever seen one properly slip, only jump off towers at weird angles.  And their grip strength is amazing!  Is it a supernatural ability, like eagle vision?
gpt
The Precursors a resemble humans at the peak of physical perfection. This is likely due to their particular brand of superscience having the ability to maintain their bodies at the limit of their biological potential. We can presume that at some point in the past, they had the opportunity to embrace a more (for lack of a better word) transhumanist philosophy, but their culture either valued biological life over cybernetic life, or they feared what they might become, or both. 

We can therefore infer that culturally they fully embraced this ethos, and it probably became a pretty common touchstone to take joy in exercising that biological perfection, and what better way to do so than improvisational free-running? It's something that the massively parallel-processing humanoid brain is easily capable of that appears to be very difficult to match with robotics, judging by 21st-century attempts at the problem. 

Consider: We can make robots that can gracefully navigate a flat plane or regular stairs. Our robots that are capable of handling irregular terrain are ugly, clumsy, and slow. Even once we crack that problem, it will probably take a long time to rid ourselves culturally of the prejudice that robots are clumsy. It's not far-fetched to think that the Precursors use the act of freerunning as a cultural synecdoche for everything they embraced as a culture when they rejected the path of transhumanism. Weirder traditions have been formed.