We do. The argument here is that there are two equivalent interpretations but that one is more fundamental (or closer to actual reality anyways) than the other

We do. The argument here is that there are two equivalent interpretations but that one is more fundamental (or closer to actual reality anyways) than the other. But this is mostly a result of the starting point taken by Einstein and then everyone understandably accepting that as the more fundamental thing. Even if no one ever finds a way to mathematically and equivalently derive GR from flat spacetime + gravity is a force first principles, it is certainly a lot easier for humans to understand gravity as being a force, and the curvature of spacetime as being other distortions on flat spacetime, not unlike the various 3D->2D projections we use for maps of Earth. Pedagogy matters. [Notice that I'm not describing the distortions that one gets when mapping GR to flat spacetime. I want to leave that to the reader, though I might pop up and reply with a list later if someone asks.]