I'm not sure that Waymo's lawsuit is the existential threat to Uber's self-driving program that other people think it is.
But if we grant for a moment the premise that the lawsuit could substantially set back Uber's program if it is won, and that it has a decent chance of winning, then what is the incentive for Google to settle? Uber doesn't just get to decide to settle unilaterally.
If we don't grant that premise, what is our basis for believing that the premise is untrue? Personally, I don't claim to really understand the ins and outs of these kinds of lawsuits, and am comfortably agnostic.