Yeah pbn networks wont work in competitive insurance niches, competitors will out you...
You're right to say that competitors can out "you," but that's isn't universal. It's simply a matter of risk vs reward and the strategies one chooses to when ranking. To use such a definitive term as "wont" is 100% FALSE. Networks have worked, do work, and will continue to work. The key is whether or not a competitor can reverse engineer your strategies and how frequently you keep up with the latest SERP changes. More importantly, nobody should be afraid of what a competitor "can" do. Just focus on winning and getting leads. Adapt, improvise and overcome.
On a side note, I really enjoyed your comments in Glen's book.