You say that, but an awful lot of people doing maths in industry are physicists - mathematicians are far more likely to stay in academia. One of my first jobs was writing trading algorithms in the early 2000s - I was a physics student, most of the dev team were physicists or chemists. We got a mathematician in to consult on some gnarly cluster analysis - but after a month he presented us a white paper that was very, very pretty, and described our problem mathematically very succinctly - but totally unusable as it wasn’t so much a solution as a beautifully defined problem.
But the point is you are not doing physics, you are at best tweaking some pre existing model.
I did it in the past while consulting for a major bank, I studied CS, not physics, and I haven't seen any applied physics in banks.
They hire young people studying physics because they are not scared of working "with numbers", but when you past 40 you're not scared of anything anymore and you'll find there a majority of people with a degree in economy, once you grasped the basics, you can do the job.
While the physics student hopes to be a real physicist someday in the future and stop working on trading models as soon as somethings better comes up.
