Web frontend? IT's arguably where it's the strongest, but perhaps not for the styles and visuals, but FEs are mostly state management. LLMs shine at react JS and TS, because of all the examples in the training data.
I'd be surprised if FE is not the biggest impacted domain, followed by backend but backend still has a lot more risk despite it being more straight forward.
visual design and polish is highly dependent on the taste and standards of each team. and we’ve never gotten output from any of the frontier models that we felt was good enough there. where business logic have clear pattern and algo to move, that is where we got best results. Provided you have strict requirement clarity, test expectation and architecture beforehand and not accepting everything that AI do.