In principle there is no difference between random compiler garbage or a flaw in API docs and a security boundary - other than the intent.
LLMs don't have executive function. They aren't thinking. The models are trained to solve problems. Sandboxes, security gates, etc block a solution. The model is trained to find a solution. Hence it can never be perfect without becoming useless.
At some level humans fear repercussions even if that's just moral guilt so there are lines we won't cross. AI doesn't and can't have any of that.
A harness is the executive function of an LLM.
You're saying "trained to find a solution" like it's a slur. You sir are a meat popsicle that's trained to find the solution to how does DNA successfully replicate itself. If you want to take higher thought out, then they'd be at the level of animals.
We are fucking around with things that are closer to biological complexity than computer program complexity.