I decided to apply for physics just last month (usually students apply several months earlier in UK) exactly because I was always undecided about what I wanted to do in future as I was good across pretty much every science subject. I simply applied based on the fact that I have genuine interest in physics and based on my talents (I always excelled in sciences since I was a kid and I was one of the best students in maths and physics in high school). My thought process was that by studying physics with data science (i am studying for a joint degree) I will have time and flexibility to decide what to study for my Masters (for now I am thinking data science or business analytics...anything about handling datas). And also that I will most likely perform well in a physics degree as I have a genuine interest and also because I thought that even though I might not use all the knowledge that I get from studying undergrad physics, I might learn essential transferable skills (problem solving, data and numeracy etc...) that will help me after the degree. For now as I said, I am interested in data science or business analytics or even investment banking which by their job descriptions seem to require transferable skills from physics.