I think that everyday life romantic attraction also often has strong elements of transference in it. It's normal and definitely not a phenomenon created by therapy, just sometimes used in therapy for analysis. I also think that attraction to a T is not necessarily pure transference at all but that aspect is often expanded and intensified as the T typically (in a good case) does not engage in that way or reveal as much about themselves as in usual encounters between people. In everyday life, most often when attraction is one-sided, it will gradually dissipate and people will stop engaging as they don't have matching interests. In therapy though, the client keeps going and talking about very personal things and the T will not reject the client straight, which can reinforce the feelings and fantasies.

With my last T, there was some clear mutual attraction that kinda lingered throughout my seeing him but it remained mild and kinda pleasant/energizing. It was just present and we never really addressed it in depth as that was not my interest - I knew very well why I found him attractive. It was not unique at all, there have been many similar attractions in my life before. So it was clearly part transference but also real in a sense that at the time he and our interactions triggered it.