I agree, and I use the default camera app more than the iNat app for taking photos. But using the iNat app allows you to immediately get an accurate location (and know exactly how accurate it is), which is important. I’ve definitely been burned by taking photos quickly with the camera app while in the field and not having any location data, or highly inaccurate location data, recorded with the photos.
For non-smartphone camera discussion, please check out https://forum.inaturalist.org/t/good-cameras-for-nature-shots/1064
For a discussion about smartphone macro lenses, please see: https://forum.inaturalist.org/t/macro-lenses-for-smartphone-cameras/9112