My understanding is that modern mobile phone cameras do heaps of "stacking" across multiple axes focus, exposure, time etc to compose a photo that saves onto your phone. I believe its one of the reasons for the multiple cameras on most flagship phones, and then each of them might take many "photos" or runs of data from their sensors per "photo" you take. id love to see a good writeup of the process, but my gut says exactly what they do under the hood would be pretty "trade secret"ie.

Can any mobile cameras focus close enough to be useful for macro? Maybe you can buy a third party add-on lens?