There are tons of ways to avoid a jury panel. You find any sort of prior art and patents, along with any suits, simply vanish; you file a challenge with the patent office for reexamination, an expert there decides it's invalid, the case disappears.
You make it sound easy, but the patent office is severely overworked. Also, does the case just “go away?” Or do you have to file a motion to dismiss on the grounds that the patent is invalid?
That’s highly nontrivial. (And by the way, almost no one uses reexam anymore. It’s all about IPR these days.)