Did anybody, including the rightsholders, come out ahead on H265? From the outside it looked like the mutually assured destruction situation with the infamous mobile patents, where they all end up paying lawyers to demand money from each other for mostly paper gains.

Why, the patent office did. There are many ideas that cannot be reinvented for the next few decades, and thanks to submarine patents it is simply not safe to innovate without your own small regiment of lawers.

This is a big victory for the patent system.