When it comes to low light you certainly can. I have a 6s and it isn’t worth taking a picture in lower light environments, that’s no longer the case.In terms of what marketing from social media providers, big internet enterprises etc. is telling their customers, I agree. For the vast majority, snapping pictures with a mobile phone will be sufficient, because the results will only be watched on a small mobile screen. But is anybody seriously thinking, that he can differentiate the picture quality taken from an iPhone X or iPhone 8 or iPhone 7 ... from the picture quality of an iPhone XS / XS Max when watched on a little iPhone screen? No way. So why pay a lot of money for a new iPhone with a better camera, when picture quality basically stays the same, when watched on a small screen?
However, the general point you’ve made still stands.