Everything I've read about the DJI sensors indicates the best IQ is pretty much wide open - it's not like a DSLR where a lens is stopped down to hit the sweet spot.Right, you can't really compare something with a half inch sensor size and a fixed aperture to something with a one inch sensor and variable aperture and expect the picture quality to match.
So IMHO the aperture is only a big deal for video as a control on frame rate. That can be addressed with ND filters.
The sensor size is a big deal - essentially they do tricks using a quad Bayer filter to get the 48mp. It's still really a 12mp at the core of it.
Whether the IQ is up to snuff - that's a personal decision.