I understand why you need the smaller focal length to maintain the same FOV, but why does the image look more blurry for the phone? My general understanding is that by zooming in you loose that crisp-ness, but if there was no need to zoom in wouldn't the two images be somewhat similar in quality?
I think the reason for that is the small sensor? since it collects less light, there will be less detail in the resulting picture. If the sensor was the same size, I would assume that their resolution would be equally good.