I agree with @lookingforward that major does matter - no U wants 90% econ majors (or CS, or whatever). It matters less there than many UCs or other Us where admits are by major.
And it may be, or have been, useful to be interested a less popular major than the school is “known for”, as was the case at Stanford awhile back with humanities majors: https://www.nytimes.com/2013/10/31/education/as-interest-fades-in-the-humanities-colleges-worry.html
HOWEVER, you can’t convincingly choose, say, French Literature without having studied French or been active in related ECs.
So, be true to your own interests - if it’s Physics and Econ, great. You might double, you might choose one, you might go a totally different way. But if those are your interests and what you are good at, say so and show why.