Yes and no, it will kill the "I ran a nessus scanner and charged you 8k for it" kind of pentests but not the core of the service market IMO. Pentesters will be more efficient so I guess this could be considered a slash in hourly rate if they kept the same pace. LLM are good at getting signals but actual hacking it is still meh.

Juniors will have a hard time that I agree. The current level of findings of LLM is at their level.

I disagree with you about the first paragraph but have to say that, distinctively to the security and the services markets, you can't say "juniors will have a hard time of it" without also saying "this is going to fundamentally disrupt services budgets". The two statements mean the same thing.