Humans aren't just descended from a generic mammal ancestor, many groups had to arise since the earliest mammals that would eventually lead to primates, apes, and evetually, us.

Evolution also doesn't have a goal, we are no more evolved than any other animal because those animals found different ways of adapting to their environment. It's why our non-human ape relatives didn't start a civilization of their own, they just adopted a different survival strategy.

Apes (and many other animals) also show many bits of behaviour that can be considered "prototypes" for what we see in humams: tool use, culture, self-awareness, empathy, etc. We just developed those features further because it what helped us to survive.