Would you make the argument that everyone should be using $200 chromebooks?
If not, then why would one make the argument that anything more expensive than a chromebook is crossing some kind of threshold?
What are those different needs? What do the top end phones do that the mid range phones do not, other than take better photos? Battery life is comparable, screen size is comparable, they run the same apps. I'm struggling to think of a single reason (other than the camera) why people buy high end phones anymore. There used to be a big difference in quality, but that gap has pretty much evaporated.
The advances very much do trickle down. Whether you would personally buy it or not.