An expert level human doesn't have to be expert at every programming category. A webdev wouldn't spot a use after free. A systems engineer wouldn't know about CSRF. That is if both don't research security beyond their field. Requiring a programmer to apply their knowledge to an arbitrary system is asking too much. On the other hand and LLM can be expert level in every programming field, able to spot and combine vulnerabilities creatively. That is all pretty hard and I don't think an security expert with vast knowledge would say "that's easy".

My point is that more experienced programmers are better at security on average, not that they are security experts.

I would think pwn2own competitions would signal the opposite. I'm consistently and often amazed at how a unique combination of exploits can bring a larger exploit and often in ways that most wouldn't even consider. I think it takes a level of knowledge, experience, creativity and paranoia to be really good with security issues all around as a person.

> essentially none of them have the ability to apply their knowledge to identify vulnerabilities in arbitrary systems.

I've found it to be the opposite. Many of them do have the ability to apply their knowledge in that fashion. They're just either not incentivised to do so, or incentivised to not do so.