Focus on something you expect AI not to exceed professional humans at in the next couple of decades. If you're convinced there's no such thing, then I wouldn't worry so much about career choice.

For a concrete answer in tech, have a look at AI development itself. Keep abreast of what OpenAI and their competitors identify as open problems and orient your academic career towards working in them. The object level questions will change while you're in school; the goal is an "intercept trajectory" where what you study just before you graduate is the state of the art.

Alternatively, highly regulated professions (medicine, law, civil engineering to name a few) are likely to continue to employ bright humans long after AI can do the job just because no-one will be allowed to use AI there.