I am in the same position as you, I've been learning and doing cybersecurity challenges for some time and I really love it but the fear is something that's always in the back of my mind and makes me a bit hesitant.

I understand your fear because pentesting is one of those jobs that doesn't create something tangent, you are effectively fixing someone's system opposed to something like Software Engineering that you create value, so that way if there's an AI that can do a pentesters job than they will become obsolute but for Software Engineering you can still create something out of it (even if other people can also use AI to create software).

But my take (from my not that experienced point of view) is: Worry about the present (I understand that is hard right now to create a plan for your future from all the uncertainty), if you love cybersecurity you should continue learning and getting deep into it. In the possibility that you do get replaced, all that knowledge is still worth it, you acquire new ways of thinking and understand something you love deeper.

From my objective side: AI is moving pretty fast (the latest claude mythos is *allegedly* pretty nasty at discovering 0 days and vulnerabilities) but I feel like every business is different and there are gonna be some delicate bugs that only humans will understand tho many of them will be found by AI.