Improvement in what way and over what previous phone? The parent mentioned a number of metrics.

Near the end of the article it says:

> We’re already at the point where marginal buyers in the poor world are getting priced out of the smartphone market. We’re rapidly approaching the point where buyers in the rich world feel the same thing.

So it predicts that phones we buy are next.

What does it improve, in practice? For myself, I need my phone to make phone calls, take photos/videos, occasionally run apps, and to be a wifi hotspot. My iPhone 6S did all of these well enough that I only upgraded it recently because I dropped it and bent the power button. My new phone has a slightly nicer camera and better battery life, that’s about it.