The 48 MP sensor can be used in a close-up mode with 24 MP resolution. That's the only deviation that keeps things at a higher quality.Thats what I meant... magnification, I'll fix that above so there is no confusion. All lenses are fixed magnification, all lenses have their own sensor, all of the lenses can only "zoom" digitally.
If you look at mirrorless camera sensors' support for 4K, some throw away a lot of pixels to capture 3840x2160. Some can't do 4096x2160 (Cinema 4K) at all.
Having toted around $10,000 worth of equipment to skate parks, I wouldn't even think of using a current phone for doing a major project, but it can be done. The best camera for the job is often the one you have with you, no matter what the quality is.