> Exactly, the legal system's job is not necessarily finding the truth.

The system purpose is to try and find the truth, because that helps society function, but is imperfect. It is good enough, so far, to keep society functioning, though its imperfection allows injustice to happen.

> It's who can convince the judge/jury better even if they use nasty tactics.

The adversarial system[1] does result in nasty tactics emerging, and I think there is room there for improvement.

[1] https://en.wikipedia.org/wiki/Adversarial_system