Some of the points in the article are unconvincing.
"Yes, we now have cameras with OK image quality at ISO 25,000, but who really cares?"
I'd say that many people cares. First you have the group that Michael dismiss as "camera nerds". Be that as it may, those people probably contribute to the bottom line, and affect prospective buyers outside of their own kind.
Secondly (and more importantly, in my view), using a camera in low light is an important usage for many regular people. They may not carry a stand at all times, and their subject may not be a (slow moving) golden sunset. For these people, being able to shoot passable images of their kids at some school event without the horrible built-in flash, is a great feature, and one that cell-phones does not do very well. If there is movement in the scene, and you want some DOF, and flash is unavailable, good ISO performance is a great feature.
"A high quality lens will always trump the sensor when it comes to producing superior image quality"
Like most bold statements, one is bound to found exceptions to this "rule".
Many have speculated that once digital camera development slows down, we will return to 70s/80s DSLR sales figures (number of units? number of dollars?). My question is what the complexity of digital design does to "system/enthusiast camera market of 2020" vs "system/enthusiast camera market of 1982". Because it seems that we will never return to the situation where there were umpteen manufacturers each covering their own small niche. Rather, it seems that we will have 2-3 giants and the rest will (more or less) disappear.
I agree with Michael that a lot could be done to make camera use more of a joy. Much like how Apple did not invent the mp3 player or the cell phone but sure made the experience into one that the masses appreciated. Not saying that mp3 players and cameras are the same thing. Perhaps this is an area that will get more attention once the image quality stops improving.
I believe that an "enthusiast" today have access to decent tools with a consumer system camera, a consumer laptop, aa A3 photo printer and Lightroom/Aperture/... It does take some patience to get everything working "close to optimal". I.e. color management is still way beyond most people. I think that if the industry was ever capable of agreeing on some supported standards for how these things connect, behave etc, a lot more people would have better results. Non-proprietary raw camera file formats, automated download/matching of printer/paper profiles, working OS/computer/display exchange of (pre-recorded) display response, sensible printing menus,... Without resorting to least-common-denominator sRGB / manufacturer-proprietary quality/progress-limiting tactics.
-h