No one would deny these are improvements. But that's about all they are: incremental improvements. What Apple didn't show yesterday, and hasn't shown since the release of the original iPhone in 2007, is true innovation.
Admittedly, Apple is the only company expected to innovate while everyone else is expected to follow suit. But if anything, the past several years have just shown the reverse.
My take could be summarized by the last few paragraphs of this fantastic article about entrepreneur Peter Thiel:
phones went from 2" screen flip-phones to the smartphones. The equivalent of the home PC to laptop. In some ways more impactful. So a similar evolution is a long way off.
And yeah, we have bigger things to worry about than pixel-density, but I don't see the point other than to ruin our fucking day.