Personal identity deals with philosophical questions that arise about ourselves by virtue of our being people (or, as lawyers and philosophers like to say, persons).This contrasts with questions about ourselves that arise by virtue of our being living things, conscious beings, material objects, or the like.
The question of personal identity is about numerical identity. This video is about numerical identity. You're talking about qualitative identity. Identity politics and so on is not about numerical identity - there's no confusion over whether person X is the same as person Y - it's about qualitative identity.