I have done both strict back-end, strict front-end, full stack, QA automation and some devops as well, I worked in an all Linux shop where we were encouraged by great senior devs to always strive for better software all around. I think you're right, it mostly depends on your mindset and how much you expose yourself to the craft. I can tackle obscure front-end things sometimes better than back-end issues despite hating front-end but knowing enough to be dangerous. (My first job in tech really had me doing everything imaginable)

I find the LLMs boost my productivity because I've always had a sort of architectural mindset, I love looking up projects that solve specific problems and keeping them on the back of my mind, turns out I was building myself up for instructing LLMs on how to build me software, and it takes several months worth of effort and spits it out in a few hours.

Speaking of vibe coding in archaic languages, I'm using LLMs to understand old Shockwave Lingo to translate it to a more modern language, so I can rebuild a legacy game in a modern language. Maybe once I spin up my blog again I'll start documenting that fun journey.